ESAC Astronomy Club

Visible sunspots

2011-10-23T10:48:00.017Z

The following mosaic was acquired on 14 October 2011 from ESAC with Michel's Celestron newtonian (1m focal, 20cm aperture) and a Baader film filter. Several sunspots groups (1314, 1316, 1317 and 1319) are visible in the image. Another smaller group is seen to the left of group 1319, but it quickly fainted in the following days. We named the group 1319 informally "the Canary Islands", due to the resemblance with the topography of these islands.

This other image was taken in H-alpha with the Solarmax Coronado and shows several dark filaments, along with the sunspots. This image can be compared with images on previous days (check this previous blog entry).

This last animation shows the position of the sunspots and other features in both visible and H-alpha wavelengths.

Meteor Showers

2011-10-16T15:10:00.009Z

The following animation shows a faint meteor that I captured from Barcelona during the Draconid Meteor Outburst on October, 8th; 2011 at 20:49 UTC.

The Full Moon light and very high clouds disturbed seriously the observation of this meteor outburst. So, in one hour, I observed only 5 meteors and captured in video the one in the animation. As I was there 1 hour observing... it makes a rate of 1 moderately bright meteor each 10 minutes. Not optimal but at least in this event I observed more than one...

Reviewing my older meteor observation videos, I found this one captured during the 2004's Perseid meteor outburst. It shows a very bright meteor and its trail imaged from Majadahonda on August 12th, 2004 at 2:15 UTC.

Next meteor outburst are:

Orionids on October 21st with the Moon rising after midnight

Leonids on November 17th with the Moon rising around midnight

Geminids on December 13th with the Moon in justs past full

Dust lanes in Andromeda

2011-10-14T09:40:00.002Z

A small portion of the Andromeda galaxy (M31) showing dark dust lanes. The bulge and nucleus have been highly saturated with the chosen brightness scales. Stack of three exposures (total time 300 sec) and the usual equipment.

An active Sun

2011-10-13T18:20:00.025Z

More H-alpha images of the Sun on 11th October 2011, taken from ESAC with the Solarmax Coronado scope.

An enormous prominence is seen on the top of the Sun limb. The inset shows a magnified image, using a 2x Barlow, with an Earth to scale for comparison. We imaged this feature for ~3h, but the sequence shows little variation of its visible shape. This is a quite stable prominence, at least compared to the highly dynamic prominence after the X1.4-class flare on Sep 22nd .

There are several sunspots visible, and some dark filaments. Other interesting prominences are seen, like a broccoli-shape one on the right of the image.

This big prominence on October 11th seems to have grown from the one observed on October 09th. It was not present anymore on 14th October, as displayed in this animation.

The Sun is keeping a high activity these last weeks.

Dumbbell "revisited"

2011-10-11T10:20:00.004Z

I have imaged again the Dumbbell nebula (M27) with the Orion Starshoot camera and my usual equipment. A single 120 sec unguided exposure with neither dark nor flat subtraction (but with the TEC switched on). I'm eagerly awaiting the opportunity to test my homemade autoguiding "gadget"!

Sunday Sun

2011-10-10T12:23:00.009Z

On Sunday 09 October, Leo, Michel and Miguel tried some auto-guiding set up. We took this composite (2 images) of the Sun in H-Alpha,using the Coronado Solarmax.

Sunspot Group no.1302, 22 Sep 2011

2011-10-04T07:50:00.011Z

Hydrogen Alpha image sequence of the sunspot group 1302 and the prominence associated with the X1.4 class solar flare which peaked around 11:00 UTC on September 22nd, 2011.

The images have been captured from ESAC, with a Coronado Solarmax 70 Telescope.

Time coverage: 11:07 UTC - 14:40 UTC

Rate: 1 frame/minute

Michel, Leo and Miguel, dismounting the telescope after observation.

An afternoon in the Sun

2011-09-15T10:57:00.013Z

On September 09th we observed the Sun in H-alpha at ESAC, in front of Leo's office.

We used Leo's Coronado on Michel's Celestron mount. The attachment point was tied with a hand-made fixation by Manuel, that held well during the observation.

After direct observation through the eyepieces, we tried two types of cameras to capture the images. Here it is a mosaic image of 5 frames (~1 min video), with Barlow and the Toucam.

The image processing was as follow:

The original sequence (video) was shot slightly dark not to saturate the pixels
The 1 minute sequence was stacked into an image
The image was stretched down to DN 85 to enhance the disk features
Mosaic was built with Photoshop with slight intensity adjustments.
A color map was applied in Photoshop to show in the same image the limb features and the surface details, with a natural color

This image was taken with the Canon EOS DSLR from Manuel (stacking 24 images of 1/20 sec).

Here it is the SOHO EIT304 image closest to the ones above (~18:00 local), for reference.

Iridium Flare

2011-09-09T14:30:00.004Z

On 2011-08-05 between 21:30 and 21:32 UTC, I imaged an Iridium flare with a Canon EOS DSLR camera fixed in azimuth an elevation. The track and the change of brightness is very clear in the image.

The flare was produced by Iridium 60 and it achieved magnitude -5 at the location (40.184N,6.305W) in Boada (Salamanca-Spain). Estimated maximum magnitude was -8 at the flare centre located at a distance of 10 km. Central position of the flare in altitude and azimuth was (40, 70(ENE)). I recommend to observe these flares because it is quite impresive event. During few seconds the flare is the brightest element in the sky. Unavoidable to use heavens-above to forecast the flares in your location.

Jupiter through the Club's telescope, 30 August 2011

2011-09-08T11:50:00.010Z

This image was taken with the Phillips Toucam and the club's telescope (Celestron CGEM, 925 EdgeHD) on 31st August around 2am, by Manuel Castillo, Santa Martinez and Miguel Perez Ayucar. A Barlow magnification lens was used to augment the size of Jupiter. The viewing conditions were poor, so we observed Jupiter between stratus clouds. The image is a processed (Registrax5) stack of a 2min video using the webcam.

Jupiter, visible

We tried also the IR filter, but we could not see the planet! Probably due to the bad cloudy viewing conditions.

The Swan

2011-09-08T10:09:00.003Z

Here's a picture of the Swan nebula (M17), very close to the Eagle. This was done in just 2 minutes (2 x 60 sec) with my usual equipment.

Still learning...

2011-09-07T13:19:00.003Z

The Eagle nebula (3 x 60 sec exposures). Not too sure on how to convert the raw B&W exposures into colour... anyhow, the dark pillars and patches of the nebula giving the characteristic "eagle" shape are clearly seen there.

2011-09-06: More Supernova Images

2011-09-07T08:31:00.021Z

Last Monday, around 23:00 UTC, I tried to take a picture of the supernova in M101 from a dark place in Salamanca (Boada) using my C8 with its default mechanical fork mount. It was aligned manually using the AR and DEC scales together with an illuminated micrometric reticle eyepiece. Without any computerized aid (i.e. no GOTO function)! As imager I mounted a standard Canon EOS DSLR in the prime focus together with a focal reducer to convert the usual F10 of the scope into an effective F3.3. The purpose was to configure a very fast imaging ensemble. However, this configuration has the inconvenient of a significant image distortion out of the optical axis. The used focal reducer design is not able to flat the prime focus over the large size of the Canon CMOS sensor. Despite of this problem, the alignment and imaging configuration allowed non guided exposures of 3 minutes. Finally, the Moon limited the effective exposures to 90 secs.

As a first test for the alignment, I tried to image M51. The image below shows the result. It has been composed stacking 4 exposures of 60 secs. Later I found that M51 houses a recently discovered SN. It is marked by a red arrow in the image. For SN identification, this image can be compared with another image of M51 that I posted here on 2007/06/22.

Then, I pointed to the main target of the night and I take several exposures. The following image shows M101 and its SN signed by a red arrow.. It is the result of the stacking of 6 exposures of 60 secs and 4 exposures of 90 secs.

My final impression of this experience it that the results are not bad, specially if it is considered that they are produced with a manual alignment.

Supernova sn2011fe update

2011-09-07T07:50:00.008Z

On Sunday 4th, I managed to image the galaxy again from the darker skies of Robledo de Chavela with my usual equipment (Celestron Newton reflector 150 f/5, CG5-GT GoTo mount and Orion Starshoot DSI II imager). Thanks to a careful polar alignment, this time I could take several 2-min. exposures. The image shown is a raw format image (i.e. no color conversion) created from a stack of 6 2-min exposures of the galaxy (T=720 sec). The SN is becoming very bright!

First images with the club's new telescope (Celestron CGEM 925 EdgeHD)

2011-09-05T14:43:00.016Z

We have used the warm and clear nights in August to go out observing at ESAC. We used the ESAC Astronomy Club new telescope, a celestron CGEM, with 9,25" EdgeHD tube. Light conditions are poor on-site but we managed to get some good first images. The images shown in this entry date from the night of the 27th Aug 2011.

We tried faint objects first, the Dumbbel Nebula M27 and the Ring Nebula M57. The images are shown here. The alignment was not great so we could only apply relatively short exposures before objects were moving noticeably. Dumbbel nebula image is a stack of 8 images of 10 second exposure each, with the Club's Meade DSI camera. The magnification of the telescope (2.3m focal) is quite large so only a fraction (around half) of the bubble is seen. No focal reducer was used.

Dumbbel Nebula, M27

We also tried M57, the Ring nebula. This was much better captured by the camera. The image is a stack of 9 images of 10 second exposure time each. The central star is seen, as well as the delicate redish and greenish colors of the gaseous remains.

Ring Nebula, M57

We waited until Jupiter rose over the horizon and over the glare of our particular Messier object, the M-503, and tried the Phillips Toucam to image the planet and its moons. K3CCD was used for capturing the image sequence, and Registrax v5 for stacking and image processing. The image is generated from a webcam clip of 1 min duration and black&white mode.

Jupiter in b&w

The last image is a color one with the Toucam, 2 seconds 'avi' clip. K3CCD was used for capturing the image sequence, and Registrax v5 for stacking and image processing. The Red Great Eye is noticeable in the right side of the South band. Also Io (left), Europa (right high) and Ganymede (right low) are visible.

Jupiter in color

These first images are very promising, and we expect to improve in the future with better tracking, images exposures, capture options, and post-processing.

Supernova SN 2011fe in M101

2011-09-03T18:43:00.007Z

Excerpt from the Wikipedia article at http://en.wikipedia.org/wiki/SN_2011fe: SN 2011fe, initially designated PTF 11kly, is a star undergoing a type Ia supernova event, discovered by the Palomar Transient Factory (PTF) survey on the 24 August 2011 during an automated review of images of the Messier 101 from the nights of the 22nd and 23rd of August 2011. The star, formerly a white dwarf, is located in Messier 101, the Pinwheel Galaxy, 21 million light years from Earth. It was observed by the PTF survey very near the beginning of its supernova event, when it was approximately 1 million times too dim to be visible to the naked eye. It is the youngest type Ia ever discovered.

We took this image on Friday, 26th August from ESAC (2 days after discovery). The supernova is clearly visible in the image (enclosed by a green circle), as shown in the comparison image from the KPNO Schmidt camera. The orientation is standard, i.e. N on top and E to the left. The image was taken with my Celestron 6" Newtonian reflector mounted on the CG5-GT mount and an Orion Starshoot DSI II color camera. The image is the sum of 3 one-minute exposures (we took neither flats nor dark frames but connected the thermoelectric cooler) . The sky quality was very poor due to light pollution (as usual at ESAC).

Eclipse Total de Luna (15 junio 2011) en ESAC

2011-06-24T11:31:00.010Z

Con motivo del eclipse total de Luna que se produjo el 15 de junio de 2011 pasado a las 21:20 aproximadamente, el Club de Astronomía de ESAC organizó una pequeña observación convocando a todos sus miembros y amigos, y especialmente al staff de ESAC. Aunque la participación fue más reducida que ha que ha habido en otros 'Star Parties' anteriores, acudieron en total unas 25-30 personas a disfrutar del evento.

La observación se realizó desde la zona del aparcamiento de visitantes de ESAC, situado en el interior del recinto del centro, al lado de la antena de SMOS. Esta zona es un poco más baja que la tradicional colina de la antigua antena 'up-link' de IUE, a la que no se puede acceder en estos momentos pues se construye el nuevo edificio de usos múltiples de ESAC. Por esta razón no pudimos observar la Luna desde su salida, ya en el eclipse total, hasta que no alcanzó altura suficiente sobre el horizonte, aproximadamente a las 22:20 hrs de tiempo local. La salida de la Luna en Madrid se produjo por el horizonte SE (120 grados de azimut aproximadamente) a las 21:44 hrs.

A pesar de las limitaciones, el espectáculo fue maravilloso, pudiendo observarse perfectamente gran parte del eclipse total hasta las 23:00 hrs aproximadamente, momento en el que la Luna entró en la zona de penumbra. No obstante, mientras observabamos la Luna con los diversos telescopios montados para la ocasión, entre ellos el Celestron del Club, pudimos tambien echar un buen vistazo al otro gran espectáculo de la noche y de todas estas noches de verano, Saturno, con sus maravillosos anillos, ahora ya perfectamente visibles, y sus lunas cercanas.

A lo largo de la observación que se extendió hasta las 00.00 hrs aproximadamente, nuestro compañero de trabajo y amigo Rafael León tomó algunas fotos, que amablemente nos ha cedido para poder dejar constancia del evento. Muchas gracias Rafael.

2010-11-05: A night of Planetary Nebulae

2010-11-12T14:13:00.013Z

As mentioned in the previous post, last Friday Miguel Sánchez and me expent few hours at SATAN Hill in ESAC to test few imaging and tracking topics of our equipment. The observing conditions, on spite of the New Moon, were pretty bad but still allowed to do some imaging tests. In particular, Miguel wanted to test the "Polar Align" option of the CG5 mount of his 15 cm Newtonian and I tried to do a manual Polar aligment refinement using as a reference the AR of an equatorial star to improve the orientation of the equatorial fork mount of my SCT C8. As the night conditions were not good enough to image low surface brightness objects like galaxies we selected as targets two planetary nebulae.

The following image shows the M27 Dumbbell Nebula. It was captured with the Miguel equipment and the Meade DSI CCD with 2 minutes of exposure without any additional guiding. The shape of the stars is very circular showing the good polar aligment achieved with the CG5 Mount. The image was obtained by means of only a histogram stretching using SAO Image SW. The central star can be identified without any doubt.

The Dumbbell Nebula (M27)

The next image shows the M57 Ring Nebula. It was captured with my telescope and a Canon 400D camera in the prime focus with ISO 1600. The picture was produced stacking four images of M57 with 2 minutes of exposure and stretching the histogram with AstroArt SW. As the shape of the stars is not circular, it means that something was wrong with the station of the telescope Maybe because it was very fast due to that the SMOS pass was comming.

The Ring Nebula (M57)

I cannot resist the oportunity show an image never posted here of M57 produced four years ago (2006-07-13) with the Leo's telescope (a 60 cm Dobsonian) and the Meade DSI CCD. The picture was produced stacking 24 images of 1 second of exposure. The result as you see is quite impressive. The central star of the planetary nebula is clearly visible.

The Ring Nebula (M57)

2010-11-05: SMOS track

2010-11-10T10:25:00.009Z

Last Friday, Miguel and me were at ESAC to perform some imaging& tracking test with our equipment in a new edition of the Friday's experiment "program". Between the targets that we selected, we tried to image the track of SMOS. Predictions can be done easily by everybody using the heavens-above website to forecast the passes of LEO satellites. Thus we detected pass over Valencia suitable to capture an image of the track: satellite-to-ESAC range around 1000 km and eastern pass, i.e. illuminated over dark sky. Finally, we tried and the following image was captured by us using a 500 mm. SCT Vivitar Telelens and a Canon 400D Rebel at ISO 1600 and 30 seconds of exposure.

I have been working with the image to try to estimate the SMOS intrinsic magnitude (not reported yet). It can be very useful for SSA and other operational events, specially in the case when a satellite must be localized to have an independent orbit assessment (e.g. a satellite radio black out... like in the case of XMM recovery. But, I must recognize that the capture was not a well planned experiment. As at that moment I was not sure about the effective field of view of the telelens, the imaged area didn't covered enough good stars to localize easily reference star brightness. In this case, it is very difficult... even with the Mount Palomar Survey plates... ;) ... Apart from the field distortions introduced by the SCT Telelens (no field correction, vigneting, etc), the main difficult was that not all the star-like features are real stars... With the fast changes of arrangement... I forgot to take some flats and darks and now I cannot discriminate these features... sometimes they can be well identified with the colour but in this case the image was taken in gray! In consequence and resuming, I'm afraid that by now I can forget to use these images to derive the intrinsic SMOS magnitude. However, some lessons can be learned from this experience for the next trials that for sure, we will perform very soon...

To avoid tracking problems:

Select the equipment: field of view (FOV) is very important!
The equipment must be stationed carefully... not in 15 minutes!
Analyse and Plan carefully the areas crossed by the track to be able to change from one area to another. In this case, I tried first with a well prepared area close to Cassiopea but the capture failed due to a FOV problem (not well known for the used SCT Telelens). After the fail I moved very fast to Pegasus without enough time to assure the pass and identify the area. Fortunatelly, it was catched up!

To reference the images: The FOV should be wide enough to capture bright starts easy to identify in the catalogues: preferably tracing constellation stars.

To correct the images: some darks and flats must be taken just after or/and before the imaging.

2010-10-26: Significant Solar Activity

2010-10-28T09:40:00.015Z

The following picture was captured on 2010-10-26 at 12:58 GMT from Majadahonda with a C8 SCT with a Canon 400D in the primary focus. It shows the solar photosphere with the sunspot groups 1117 and 1115 and faculae near the limb.

Solar photosphere on 2010-10-26T12:58 GMT

Just later, two videos of 15 secs were captured attaching to the primary focus a Phillips Toucan Pro Camera with a NIR blocking filter. The pictures below were produced stacking the individual frames using Registax. In these images more details of the sunspots and their umbra, solar granulation and faculae can be observed.

Sunspot group 1117 on 2010-10-26T13:05 GMT

Sunspot group 1115 on 2010-10-26T13:15 GMT

The following pictures show cromosphere details in H-alpha. These images were produced stacking two videos of 15 secs captured around 14:00 GMT with a Phillips Toucan Pro Camera and a 2x Barlow attached to a Coronado PST. In the first image, cromosphere filaments and spicules can be observed above and around sunspot group 1117. The active area between sunspots suitable to produce flares is quite evident in the image.

Solar Cromosphere on 2010-10-26T14:00 GMT

The next image shows a large eruptive prominence produced by an active region behind the limb.

Eruptive Prominence on 2010-10-26T14:15 GMT

2010-09-29: Jupiter just after the oposition

2010-10-22T15:22:00.003Z

This is an image of Jupiter taken from Majadahonda on 2010-09-29 with a Celestron 8" SCT. The camera was the usual Phillips Toucam Pro with a NIR cut filter and a Barlow x2 lens. It was used to capture a video of 15 seconds that was processed with Registax to stack all the individual frames. The picture is the result of this processing.

Pruebas con Camara Nikon D50

2010-10-21T09:54:00.005Z

He aquí tres pruebas rápidas hechas con nuestro Telescopio y una Nikon D50 (E. Ojero) enchufada a él con un adaptador especial para cámaras SLR Nikon (A. Talavera).

1 - Júpiter con los satélites, T=1/2 seg

2- Júpiter sólo, T=1/50 seg

3 - Luna, T=1/500 seg

Star Party, viernes 15 de octubre de 2010

2010-10-20T10:41:00.013Z

Todos estabamos deseando volver a hacer un Star Party, para poder disfrutar de una noche de observación con los demás miembros del Club y con los amigos, y además poder estrenar el nuevo telescopio del Club. Y por fín lo hemos podido hacer.

El pasado viernes 15 de octubre, con una asistencia entre 200 y 300 personas, celebramos un nuevo Star Party en ESAC. Además de casi todos los miembros del Club, participaron muchos compañeros de ESAC, con sus hijos, familiares y amigos. También acudieron muchos amigos de asociaciones de astrónomos amateurs de la zona de Madrid a través de la llamada de algunos miembros del Club.

Tuvimos un cielo limpio de nubes aunque la temperatura bajó bastante. La Luna estaba en cuarto creciente, lo cual hizo difícil la observación de algunos de los objetos débiles pero resultó ser un gran atractivo para las personas que se “estrenaban” en la observación. Es indudable que la magia del “terminador” y las largas sombras de las montañas Lunares son un gran atractivo para los que se acercan por primera vez a un telescopio.

Muchos participantes trajeron sus telescopios, con lo que batimos todos los records en número, tamaño y calidad de los mismos: el magnífico Dobsoniano "Obsession" de 63,5 cm de Leo Metcalfe, otro Dobsoniano de 40 cm de Fernando y Leo, dos magníficos Celestron EdgeHD de 27,9 cm de Carlos Anaya y de Patricio, el Celestron EdgeHD de 23,5 cm del Club y otro similar que aportó Carmen Morales por el Laeff, el Meade de 20 cm de Eugenio Salguero felizmente recuperado, dos Newtonianos, el de 20 cm de Michel Breitfellner y el de 15 cm de Migeul Sánchez, la maravilla de Takahashi de 9 cm de Eduardo y Paloma, el Newton de 7 cm de Miguel Pérez, los ETX-70 de Ricardo Pérez y Roberto Prieto, etc.

Participantes montando los telescopios

A lo largo de las casi cuatro horas, todos pudimos ver la Luna, Júpiter y sus satélites, Urano, Neptuno, Mizar y Alcor, Epsilon Lyra (doble doble), el cúmulo globular de Hércules (M13), las Pléyades, la galaxia de Andrómeda (M31), la nebulosa anular de Lyra (M57), la nebulosa Dumbbell (M27), y otros objetos. El gran Dobsoniano de Leo nos siguió deleitando con su extraordinaria luminosidad a pesar de que el ordenador de guiado se había quedado sin baterías. Pero la pericia de Leo permitió que la larga cola de niños y adultos que querían pasar por el telescopio, no resultasen defraudados. Tambien Carlos y Patricio nos ofrecieron magníficas imágenes de Júpiter y la Nebulosa Dumbbell, mediante filtros de color y un estupendo binocular.

Sesión de observación

Antes de acceder a la observación en la colina de la antena Satán de IUE, nuestro sitio favorito y tradicional de observación, el Club ofreció tres presentaciones: Luis Sanchez nos habló brevemente de lo que hacemos en ESAC, qué proyectos y qué actividades desarrolla la ESA en este centro; Miguel Sánchez nos explicó muy breve y rigurosamente qué es un telescopio y qué tipos podemos encontrar tanto para uso por los aficionados como en los instrumentos profesionales; y Eduardo Ojero nos dio una rápida visión de los objetos que podiamos observar en esa noche, desde estrellas dobles, pasando por planetas, galaxias, nebulosas, etc.

Sala de actos durante las presentaciones

No exageramos al valorar este evento como un éxito rotundo no solo de público y telescopios, sino tambien por la satisfacción de pasar una noche muy agradable disfrutando del cielo en compañia de nuestros amigos y familiares.

Participantes desmontando los equipos hasta altas horas de la madrugada

Una colección completa de las imágenes del Star Party la podeis encontrar aqui.

Star Party! More than 300 people enjoy at ESA the greatest show on Earth

2010-10-20T09:24:00.003Z

The night sky is, in every sense, the greatest show on Earth. But Madrid, like all big cities, is not the best place to enjoy it… unless you come to ESAC.

The ‘observation campaign’ organized last Friday October 15 by the ESAC Astronomy Club was definitely a success, a true star party with about 300 people –including children- gathered around a dozen telescopes.

Atendees during the observation

Guess what was the most appreciated view in the night sky? The Moon! While the Moon is usually a nuisance for astronomers –its brightness makes the other celestial bodies more difficult to see-, last Friday it was highly admired: “The Moon is a great object for kids, and for all those who are really not used to see through a telescope”, says Eduardo Ojero, president of ESAC Astronomy Club. “People love to watch the magical terminator, the line separating the illuminated and the dark sides of the Moon, where you can see the long shadows of the mountains”. Jupiter, Neptune and Urano were also in display, as well as the M13 globular cluster, M31 (Andromeda's Galaxy) and M57 (Ring Nebula in Lyra).

ESAC Star Party participants during the observations

The king of the telescopes was Leo Metcalfe’s… 63,5 cm Dobsonian (25 inches). But the new telescope of the Astronomy Club, a Celestron 9,25 EdgeHD CGEM, also behaved wonderfully on its first public appearance. There were also other smaller scopes : a wonderful 40 cm Dobsonian, two 11 inches Celestron's EdgeHD, several Celestron 8 and Newtonian of 20 cm, a Takahashi 9 cm, etc.

The star party started at 19.30 with several presentations about ESAC, by Luis Sánchez, from the SOHO team; and about how telescopes work. Miguel Sánchez-Portal, a member of the Herschel team, also explained why sometimes it is necessary to send telescopes to space to collect radiation that gets blocked by the atmosphere, such as most of the infrared light, ultraviolet radiation and X-rays and gamma-rays. Eduardo Ojero then introduced the kind of objects that would be observed during the ‘party’.

“It was a wonderful occasion for everyone to learn and enjoy with the sky”, says Ojero. “Even for professional astronomers! We spend so much time analysing the scientific data that we sometimes forget what all our work is about!”.

2010-10-09T09:24:00.006Z

El próximo viernes 15 de octubre, si el tiempo lo permite, haremos un Star Party en ESAC, al que estáis invitados todos los miembros del Club, familiares y amigos.

Tambien hacemos extensiva la invitación a todos los empleados de ESAC, familiares y amigos.

Para inscribirse, podéis hacerlo en este enlace.

El programa provisional es el siguiente:

19:00 - 19:30 Recepción de participantes.

19:30 - 20:30 Presentaciones sobre temas astronómicos.

20:30 - 01:00 Tour por las constelaciones con punteros laser. Tour de observaciones desde varios telescopios incluido el nuevo Telescopio del Club, un Celestrón 9,25 EdgeHD CGEM.

Si tenéis un Telescopio, os animamos a que lo traigáis y os unáis a nosotros en las observaciones.

Esperamos tener buen tiempo y poder disfrutar de una estupenda velada de observación.

Os deseamos un Feliz Star Party!

Primera luz del nuevo Telescopio del Club.

2010-10-08T23:00:00.008Z

Y por fin hicimos primera luz del nuevo Telescopio del Club, un Celestron 9,25 pulgadas EdgeHD CGEM. Una maravilla!

El tiempo era muy malo y amenazaba lluvia, así que sacamos el Telescopio sólo unos metros fuera del edificio B de ESAC.

Tuvimos algunas dudas !!!

A pesar de las gruesas nubes, la vista de Júpiter fue espectacular y al menos compensó no poder observar más cosas.

Estas fotos hay que agradecérselas a Carlos Anaya, miembro del Club, que tambien estuvo presente.

2009-03-17: ISS and Venus

2009-03-17T22:56:00.005Z

2009-02-19: Comet Lulin (C/2007 N3)

2009-02-19T19:25:00.003Z

2009-02-14: Venus again

2009-02-17T15:25:00.007Z

Last Saturday, shortly after the sunset, I revisited Venus again to check the performances of the set of interferntial filters made by Edmund Optics. The objective was a new checking of the atmosphere detail discrimination using the equipment described in the last post.

The following image was obtained in the visible range by means of the stacking of 85 images with the original bayer filter of the camera CCD.

In order to the reduce atmospheric dispersion, the three channels were co-resgistered to produce the following real colour image of Venus.

The next images were produced with the filters. The first one is a NIR (R:880 nm), Blue (G: 450 nm) and Near UV(B: 400 nm) false colour combination obtained stacking around 80 images to reduce seeing and noise.

The second one is a combination of two NIR bands (R: 950 nm, G:880 nm) and Blue (B:450 nm).

The quality of this image is quite impressive because the atmospheric seeing seems to be better in the NIR range than in other regions of the visible and near visible ranges.

2008-12-23: Venus in UV, Blue and NIR

2008-12-24T11:16:00.005Z

Equiped with a new set of interferential filters, I tried to image Venus from Majadahonda to check if something could be discriminated in the atmosphere using the filters that I have. The camera was the usual Phillips Toucam Pro with the following set filters manufactured by Edmund Optics: 400 nm, 450 nm and 880 nm with respectively 50, 80 and 50 nm of FWHM. The telescope was my Celestron 8" SCT. As Venus is still very far from us, I used a 2x Barlow to increase as possible the size of the disk in the camera detector. The following image is the result of the stacking of 80 images with the false colour combination R:880 nm, G: 450 nm and B:400 nm.

It is well known that the Venus atmosphere presents some UV absorvers. They are distributed in atmospheric dark bands that could be constituted by chlorine or/and sulfure compounds. It is known since the Mariner 10 captured the firsts closed images of the planet. At present, Venus Express is observing the atmosphere in UV to better understand the composition of these bands and their paper in the atmospheric circulation.

In order to detect some atmospheric detail, I tried to exploit that the Phillips Toucam Pro has some sensibility in the UV and the 400 nm interferential filter has some band pass in the near UV. However, anything was observable. Maybe the band pass of the filter should be shorter to detect better the radiance contrast produced by the different molecular especies or perhaps the scale of the atmospheric bands is very low and their removed by the stacking required to reduce the seeing.

2008-12-01: Triple Conjunction

2008-12-02T12:08:00.006Z

To be completed...

2008-08-17: Green Flash

2008-12-02T12:08:00.005Z

To be completed...

2008-06-07: Summer Globular Clusters

2008-12-02T12:07:00.003Z

M22

M12

M80

To be completed...

Yet more DSI images...

2008-08-29T21:25:00.008Z

The images below were taken from ESAC using the DSI camera and the 6" AS-GT reflector. The sky transparency was not very good and at some point got cloudy.

M27 - A single exposure of 1 minute, saved as 3-colour FITS. Histogram modified with DS9.

M57 - a single 1 minute, saved as 3-colour FITS file

M13 - a single 8 sec exposure, saved as 3-colour FITS. Two different ranges for
displaying purposes

New tests with the DSI camera...

2008-05-14T12:47:00.007Z

On May, 1st-2nd, I performed a few new tests with the DSI camera (thanks to Manuel who kindly provided to me) attached to my Newton telescope (6", f/5) and the CG5-GT mount. These are single-shot images (i.e. not an average of a number of individual exposures) and the dark frames were too short. While the quality is not very good (e.g. very noisy background), they're nice on average so I post them. Exposure times are: 60 sec (M51), 30 sec (M104), 60 sec (M81) and 8 sec (M3)

2008-02-21: Total Lunar Eclipse III

2008-02-21T17:15:00.005Z

As a first draft result of the coordinated observation, I have produced an anaglyph showing a moment of the Lunar Eclipse in 3D.

The first picture was posted in Cielo Sur in answer to the coordinated observation by Leonardo Julio, Alejandro Tombolini and Adriana Fernández from Arenales y Agüero, Capital Federal, Argentina . It was captured with a Meade LX 90 telescope and an Olympus Evolt E-500 camera (provided by Silvia Smith). The second image was captured from Majadahonda (Madrid) by Manuel Castillo using a 9 cm/F10 Matsukov-Cassegrain Telescope and a Canon400D camera at 01:56 GMT. It was selected identifying the corresponding stereoscopic pair in a sequence covering all the Moon immersion in the Earth Shadow. Alignment and scaling was performed using conventional image processing techniques.

2008-02-21: Total Lunar Eclipse II

2008-02-21T10:19:00.012Z

During the last night, the clouds were a big problem here in Madrid. We had a good window at the beginning of the eclipse. Therefore, the immersion in the shadow was easily visible. However, just after the totality, the conditions degraded a lot. Some open clouds permited to picture part of the totality but the emersion observation was quite difficult because the distribution and thickness of the clouds complicated seriously the imaging.

The following image was captured shortly after the maximum of the eclipse (03:31 GMT) with a 9 cm/F10 Matsukov-Cassegrain Telescope and a Canon400D in the primary focus at 1600 ISO and 5 seconds exposure.

Despite all these problems, I captured a sequence of all the eclipse. It can not be used to produce a video because the captures were not continuous. But, I hope that the individual frames can be used to produce 3D images of the sequence if finally somebody in the other hemisphere was lucky. As soon as I have more info I will post it here

2008-02-21: Total Lunar Eclipse I

2008-02-19T11:12:00.015Z

For the observation of the total lunar eclipse of next February, 21th 2008 eclipse, we are participating in a coordinated observation of the total lunar eclipse of Next February, 21th 2008 from SouthAmerica and Western Europe.

The main data of the eclipse is shown below:

The eclipse has different characteristics of difficult repeatibility:

- All the eclipse will be visible from both Western Europe and South America.
- It is the last total lunar eclipse in the next 7 years which is visible in its integrity from South America.
- It is the last total lunar eclipse in the next 6 years which is visible in its integrity from Western Europe.
- Before the eclipse, the Moon will pass between two bright stars: Regulus (Mg. 1,41) y 31 Leonis (Mg. 4,4).

These characteristics permit the development of two interesting activities using simultaneous observations from Europe and South-America:

- The production of a 3D video of all the eclipse combining images taken from both hemispheres. It could be the first times it is produced.
- Using the two bright stars and the Moon imaged from both hemispheres, estimation of the Moon-Earth distance by means of the measurement of the Moon paralax. It has a similar educational value than the determination of the astronomical unit by means of the Venus transit.

Complementary activities are:

- Timing of the five penumbra and umbra limb contacts.
- Timing of the umbra immersions and emersions of certain surface features.
- Timing of star ocultations during totality.
- Monitoring of possible Lunar transitory effects during the totality and the final phase of the penumbra.

Interested people from South America have been invited through Cielo Sur, an argentinian amateur astronomy webpage. Also personal invitations will be adressed. From Europe, the Astronomic Group of Madrid with some people of the ESAC astronomy club will be involved in this activity together with other teams from Spain. As observing from only one region the weather can be a problem, we have contacted teams observing from other parts of Western Europe to assure as possible the imaging of the eclipse from this hemisphere. So, ESOC & ESTEC astronomy clubs have been invited despite they have not the best weather during February.

As outputs of this activity and with credit to all the participants, it is expected to produce a stereoscopic video of the eclipse, a report gathering all the provided results and educational material for a practical Earth-Moon distance calculation.

Amateur astronomers from everywere in the visibility area are specially encouraged to participate in this event. Everybody can participate in this observation using from small binoculars to large size telescopes. A guide with details of all the observable phenomena is available here.

The main coordinator of the activities and the main author of the observation field guide is Alberto Martos. He is an experienced Moon explorer. He worked in the Madrid ground control of the Apollo missions (XIV-XVII) and Skylab and worked in VILSPA until his retirement last year in the mission control of different ESA missions (IUE, ISO and XMM). At present, he is member of the Astronomic Group of Madrid.

2008-02-09: Orion Nebula - M42

2008-02-13T16:39:00.003Z

The following image was captured from Majadahonda (Spain) using a C8 SCT with a Canon Rebel 400D attached to the primary focus. It is the result of the combination of three exposures of 60 seconds in RGB with and ISO of 1600.

2008-01-19: Mars one month after the oposition

2008-01-21T13:49:00.001Z

During the last weekend, the Moon and Mars were in a conjuntion of less than two degrees. Of course, we met for the event. So, Alberto Martos, Fernando Rodriguez and me were in the backyard of Alberto's house "Villa Urania" in Villaviciosa de Odón with all our equipment to register the astronomic encounter. The following image shows the conjuntion. It was taken with a Canon400D camera with a 300 mm APO objective around 23:45 GMT.

Of course, the real excuse for the meeting was to observe and image Mars. Still it is very close to its oposition, nearly one month after, and it is possible to take detailed pictures of the surface.

The Mars imaging was performed around 23:30 GMT with a 8" SCT with a Toucam Pro webcam, a blocking NIR filter and a two Barlow lens ensemble. The focal length of the SCT telescope is 2 meters. Therefore, the effective focal length using together one 2x and one 3x Barlow lens should be around 12 meters! (probably the effect is not exactly multiplicative... a detailed calculation should be made...). The captured video tracks were stacked with REGISTAX and the histograms modified to show the best contrast. Additionally, an unsharp mask was applied to enhance as possible the contrast of the surface details. The following image shows the final result.

The next image resulted forcing slightly the histogram and sharpening modifications.

Several video tracks were captured also using a NIR pass filter. However, the high attenuation introduced by the Barlows difficulted greatly the focussing. As a consequence any of the captures have produced acceptable NIR images.

Merry Christmas & Happy New Year from ESAC

2007-12-20T16:15:00.000Z

Merry Christmas & Happy New Year!

Joyeux Noël et Bonne Année!

Fröhliche Weihnachten und ein glückliches Neues Jahr!

Vrolijk Kerstfeest en een Gelukkig Nieuwjaar!

Buon Natale e Felice Anno Nuovo!

Boas Festas e um feliz Ano Novo!

Glædelig Jul og godt nytår!

God Jul och Gott Nytt År!

Eg ynskjer hermed dykk alle ein god jul og godt nyttår!

Kala Christougenna Ki'eftihismenos O Kenourios Chronos!

Feliz Navidad y Próspero Año Nuevo!

2007-12-01: Mars one month before the oposition

2007-12-11T10:53:00.000Z

This post shows the results of our second tentative imaging Mars close to its oposition. In this case, the people meeting in Satan Hill were Leo, Michel, Roberto and me. Again, the Leo's Dobsonian 65 cm telescope was used together with a Toucam Pro webcam, blocking and pass NIR filters and a 3x Barlow. The captured video tracks were stacked with REGISTAX and the histograms modified to show the best contrast. Additionally, an unsharp mask was applied to enhance as possible the contrast of the surface details.

The following image was captured around 2:30 GMT with the NIR blocking filter.

The next one was captured around 2:30 GMT with the NIR pass filter.

A combination of both images substituting the red channel of the firs image with the second one produces the next image.

In the north cap, the winter CO2 froze can be observed extending to the south of the polar regions. Now, as the planet is closer, both the RGB and NIR images show more details of the surface than in our previous tentative. However, the poor seeing during the observation degrades the sharpness of the images. Despite that, the observed regions can be clearly identified. The following image has been produced by Leo forzing a little the sharpening to remark some of the Mars regions.

2007-11-07: Mars two months before the oposition

2007-12-11T10:31:00.000Z

This post shows the results of our first tentative imaging Mars close to its oposition.

On November 7th, 2007, Leo and me were at Satan Hill in ESAC to try to image mars with the Leo's a Dobsonian 65 cm telescope. The following images show our best results with the Toucam Pro webcam, blocking and pass NIR filters and a 3x Barlow. The captured video tracks were stacked with REGISTAX and the histograms modified to show the best contrast.

The following image was captured around 1:30 GMT with the NIR blocking filter.

The next one was captured around 1:30 GMT with the NIR pass filter.

A combination of both images substituting the red channel of the firs image with the second one produces the next image.

The planet disk shows a well defined phase yet and both the RGB and NIR images show very well different details of the surface. The image is centered in Chryse planitia with Syrtis Major appearing in the terminator. In the north cap, the usual winter CO2 froze can be clearly observed far from the polar regions.

Comet 17P/Holmes

2007-12-05T11:10:00.000Z

After some time dedicated to other astronomical topics, I'm back to share my images of comet 17P/Holmes.

This comet suffered a very spectacular eruption on Oct. 24, 2007. In less than 24 hours, the 17th magnitude bright of the comet increases by a factor of nearly a million, becoming a naked-eye object. From this day it has been expanding while it was crossing the constellation Perseus. Now, it is vanishing and it nos as spectacular than before but now it has a diameter bigger than the Moon that can be very well appreciated by the naked-eye from very dark places.

During the first two weeks the comet was bright enough to be observed from the center of the cities. Thus, I put my equipment in front fo the window and I captured the images I show you. All the images have been captured with a C8 SCT and a Canon 400D camera with exposures of 20 seconds at 1600 ASA.

The following image shows the evolution of the coma of the comet between 3 days after the eruption and one week.

The next image is an anagliph of the previous images using the aparent movement of the comet on the stars background. If you have red&blue glasses you can appreciate a 3D view of the comet in front of the stars.

An animated gif helps to evaluate the comet growth in during only one week.

The last image was taken with 30 seconds exposure on Oct. 30 at 19:30 GMT. Later the histogram was forced a little to show the exterior green halo of the comet. It is erupted matter that emits green light because its interaction with the solar wind. It is green because its composition and it can be well observed because this matter has not enough density to reflects sufficient solar light (mainly white) to mask this emission.

Additional images of the comet showing its evolution from the first eruption until now can be found in this webpage or this one.

First test with the C150/NGT and the club's DSI camera : 17P/Holmes 3rd Nov.

2007-11-16T10:57:00.000Z

This single 30 sec image of 17P/Holmes is the very first test imaging with the 150 mm Newton telescope and the DSI camera. Due to the very rough polar alignment, star trails are evident even with this short exposure. More (and much better) images of the Holmes comet can be found here

M42 2007-10-20/21

2007-10-23T13:46:00.000Z

As the Saturday night was specially good for observation from ESAC, Leo, Michel and me met here to observe something after the moonset. Despite the good atmospheric conditions, the light pollution was important (more than other times?...), thus we pointed the telescope to one of the brightest deeps ky targets: the Great Nebula of Orion (M42).

The following two images show the results. Both images were captured using a C8 SCT with a Canon Rebel 400D attached to the primary focus. Using an ISO of 1600. The first one is the result of the combination of three exposures of 30 seconds with wide band RGB filters.

The second image is a combination of two exposures of 60 second with narrow filters Red:H-alpha and G: OIII and a 30 seconds exposure with a wide band Blue filter.

After we pointed the telescope to Mars but the images must be still processed. As soon they are, they will be posted here.

Fabra Observatory 2007-10-09

2007-10-18T10:19:00.000Z

Last week, I was with a friend, Antonio Bernal, at the Fabra Observatory of Barcelona (map) using a 1900's 38 cm double refractor (visual and photographic) measuring double star separations with a restored micrometric fil counter (from 1900 too). The following pictures show the telescope in operation.

This telescope was widely used during 100 years for astrometry and several minor solar bodies were discovered from here. As a result they have spanish names (Hispania, Barcelona, etc.). The observatory has also a huge collection of photographic plates covering around 80 years. Think about what they can produce if they are digitalized one day... However, the most spectacular achievement was the discovery of the atmosphere ot Titan in 1908 by Comas Sola, the observatory founder, observing the satellite limb darkening. It was published in 1908 in Astronomische Nachrichten and confirmed by Kuiper in 1944.

Today, the telescope is in operation but due to the high light pollution caused by the city it can be used only for some astrometric and planetary observations. The following pictures of the dome and the city show clearly the effect of the light pollution.

After its restoration, Antonio is using the telescope to measure today the separation of double stars that were reported before 1950. So, he hopes to update the double star catalogues confirming the observations and derive orbital information of the double systems. Additionally there are also public visiting tours and in special events they organize some public observations.

Sputnik-1 - 50 years anniversary

2007-10-01T17:14:00.000Z

Next Thursday, October 4th, 2007, is the 50 anniversary of the Sputnik-1 launch.

It is very surprising for me that ESAC has not any scheduled activity. Some people, me too, consider that it was the beginning of our business and it should be celebrated. The space part of course... (the astronomy part is probably the second oldest business of the human history... ). Therefore, to solve in some way this lack of celebration, I have made a simulation of the event and I post it here.

It is a Celestia simulation of the first Sputnik-1 orbits. The orbital elements are tabulated in the NORAD archives and they are valid for October 1957. After the high atmosphere drag and other low orbit perturbations caused the decay of the orbit until the satellite catastrophic reentry in the atmosphere in January, 1958. It reproduces quite well the reported passages.

The spacecraft attitude is an inertial extrapolation of the attitude of the launcher after the deployment.

The rotation period (around 6 revolutions per minute) was roughly estimated with the observed rotation of the Faraday field of the dipoles of the antennas. Rotation arund the major revolution axis was reported by Bracewell and Garriott in 1958 in a paper in nature.

A good historical compilation of the events behind the Sputnik can be found here. In the following links, some historical movies about the event can be found.

An acceptable dramatic reconstruction is shown in the BBC documentary "Space Race". Some excerpts of the series can be found also in youtube.

Bonilla 2007-09-08/09

2007-09-11T12:59:00.000Z

Following the invitation of Alberto Martos for the last Saturday, I attended to the Mirador de las Estrellas (Google Earth Link). It is the observation area that the Agrupacion Astronomica de Madrid has in Bonilla, Cuenca. There, despite the bad state of the atmosphere, we were able to capture the following images. The first one is centered in the central part of the Andromeda galaxy (M31) and the second one the Hercules Globular Cluster (M13).

Both images were captured using a C8 SCT with a Canon Rebel 400D attached to the primary focus. Using an ISO of 1600, the M31 image was captured with an exposure of 3 minutes and the M13 image with an exposure of 30 seconds. The posprocessing of the first image consisted in a HDR rescaling followed by a median filtering. The second one was produced modifying the histogram levels and aplying a median filtering.

M4 2007-08-08

2007-08-10T09:34:00.000Z

During last night I connected a Canon EOS 400D camera to my C8 SCT to check the images that can be obtained from Majadahonda. As a first test, I pointed the telescope to M4 (Cat's Eye) Globular Cluster in Scorpio (Mag. 7.5). The following picture shows the result of an exposure of 1 minute in the focal plane with the histogram modified to reduce the light pollution.

NIR Summer Experiences

2007-08-10T09:12:00.001Z

During my summer holidays in the Pyrenees, I have made some experiments combining visible and NIR images taken with a modified 3M digital camera. As chlorophyll reflects very well the NIR radiation, my intention was to verify this phenomena using the same filters that we use for astronomy. The selected target was the vegetation of the hight mountain terrains to show how it invades the different altitude levels. The following pictures show together the visible and the NIR infrared images to better appreciate the differences.

M63 2007-07-14

2007-08-01T12:48:00.000Z

The following picture is a 5 min. exposure image of the Sunflower Galaxy (M63). It was taken from ESAC around 1:00 GMT of 2007-07-14 with the Meade DSI camera and a C8 SCT with a 0.33 focal reducer. The central part of the galaxy and its structure is clearly visible but the diffuse area is only apparent because the low contrast caused by the poor darkness in ESAC.

Moon 2007-06-29

2007-07-09T16:09:00.000Z

As promised, close to the full Moon to reduce shadowing effects (2007-06-29 21:30 GMT), I repeated the multispectral imaging of the ejecta complex around Copernicus crater. The following picture covers the same area than the images posted before but excluding the Erathostenes crater. The false color combination was the same (Red:NIR; Green:G; Blue:UV). The color was also saturated in order to better appreciate the different responses.

Moon 2007-06-24

2007-06-26T12:32:00.000Z

On Sunday (2007-06-24 22:30 GMT) and from Majadahonda, I imaged the Moon in UV, RGB and NIR with a C8 and a DSI Meade Camera. I tried to check if the response of different surface materials could be characterized from the Earth surface. For this purpose, the images should be as zenithal as possible. However, due to the date, the images were taken close to the terminator. The false color combination was (Red:NIR; Green:G; Blue:UV). This color was saturated in order to better appreciate the different responses.

The first image shows the Copernicus and Erathostenes craters and it is centered in the large ejecta complex surrounding Copernicus.

The second image is centered in the Montes Apeninnus that separate the Mare Imbrium and the Mare Vaporum. The large crater of the image is Archimedes and the smaller ones are Aristillus and Antolycus.

Using this false color combination, the different surface responses can be discriminated. However, the fact that the images are very closed to the terminator difficults the direct mapping of the surface elements. This could be solved removing the illumination effects using an elevation model or taking the images as close as possible to the full Moon. This last option seems more feasible for testing...

Deep Sky Tour at ESAC 2007-06-22

2007-06-25T10:25:00.000Z

Last Friday, Leo, Michel, Fernando and me met here to try to image Venus with the UV filter and The Leo's telescope. After some trials and errors, the results were unsuccessful... it seems that we have lost some training using the Dobsonian with a Barlow... Later than the Moonset, we tried to image some deep sky objects from ESAC. Despite the light pollution, the bad seeing and a non-accurate tracking, some good deep sky images were taken. We used a C8 telescope with a 0.33 focal reducer and the DSI Meade CCD camera. The exposures ranged from 45 sec. to 1.5 minutes. Of course, we tried with some of the easiest Messier objects.

M51 Whirlpool Galaxy M82- Cigar Galaxy M27 - Dumbbell Planetary Nebula
M20 - Trifid Nebula

Celestial Line 2007-06-20

2007-06-21T13:18:00.000Z

Last night in Majadahonda, the sky cleared and I photographed an infrequent alignment of the Moon, Regulus, Saturn and Venus (from left to right). This alignment marks approximately the ecliptic. Technically it is the place where lunar and solar eclipses take place. However, during the last two days, the Moon has been eclipsing all the elements that has been encountering along the line... it seems that at least in this case the ecliptic definition could be extended a little...

Small Astrophoto Tour 2007-06-18/19

2007-06-20T08:26:00.000Z

Yet I am testing my Baader U Filter. So, I tried to take again a picture of the Venus atmospheric features with my C8 Celestron from Majadahonda. In the previous post referred to Venus imaging, I showed a firsts UV picture. But there is something strange... it seems that a ghost image appears superposed to the main image. After some research in the technical specifications I discovered that the Baader U-filter has some small transmission in the NIR. If the observed object doesn't has a large emission in the UV, the NIR contribution can achieve the same magnitude. It should explain the detection of superposed double images slightly separated by the atmospheric refraction. In consequence, to use adequately the Baader U-filter it is necessary to combine it with a NIR blocking filter or a blue wide band filter to remove the NIR contribution.

The following image is the first result after combining the U-filter with a NIR blocking filter (the Astronomik NIR blocking filter, the Baader one blocks also the UV). In order to increase the exposure, instead the Toucam Webcam Pro, I used a CCD (Meade DSI) with a filter wheel. However, due to a large seeing and the low height of Venus at the imaging, large atmospheric distortions affected the image. After the stack of 10 images with 0.7 secs exposure, this is the best I achieved. Yes... I know any atmospheric feature is visible. Next time I will image early and with a better seeing.

After the Venus set, all the equipment was mounted. So I decided to perform a small astrophoto tour. The next image is the result to combine 40 images of Jupiter of 0.003 secs each.

The image shows the M22 Globular Cluster. For the generation of this image, 80 images of 15 secs were combined.

Apophis: the End of the World is Nigh?

2007-06-14T16:09:00.000Z

Talk from Mark Kidger on June 14th, 2007 at ESAC
Download pdf

A world with oceans...

2007-06-14T12:58:00.000Z

This could be the look of the red planet 2.000 millions of years ago!

Perron et al, NATURE| Vol 447| 14 June 2007

2007-06-11: Venus in UV - First Test

2007-06-13T12:37:00.000Z

Last month I adquired a Baader U filter to observe Venus. Two days ago I did my first test with the filter using my C8 and a Toucam Pro webcam. The sensibility of the camera is very low in UV. Therefore, I used the camera at the limit of gain and exposure. The following images show the result with the webcam CCD in the focal plane after a postprocessing with Registax.

There some estructure was clearly visible in UV in the Venus atmosphere. But when I tried to use a Barlow lens to magnificate the image, I reduced the luminosity of the image out to the detection range of the camera. What to do?. To increase the diameter of the telescope ( I think in Leo's telescope...) or use a CCD with a wider detection range. However, a larger exposure can difficult seriously the seeing compensation in posprocessing...

Sun in H-Alpha 20070601

2007-06-04T10:47:00.001Z

Despite of some problems with the electrical current in the Satan site, last Friday we imaged the Sun in H-alpha using the Leo's CORONADO telescope again. The following images show the full disk and the prominences.

I post also some images of the observers and the equipment. Only Michel, Leo and Me are in the pictures but Ricardo and Luis were also here.

Sun in H-alpha 20070529

2007-05-30T10:23:00.001Z

Finally, the sky cleared and yesterday (2007-05-29), Leo, Michel and me went to the hill to test the new solar telescope of Leo. Thus, around 17:45 GMT we captured some images with a small digital camera (Werlisa SLIM 30 Pro) attached to the telescope. After some processing, the following image was produced:

The image processing was as follow:

The original caption was transformed into a grayscale image.
The grayscale image was transformed into a RGB image.
A color map was applied to each channel of the RGB image to show in the same image the prominences and the surface details simulating as possible the observed colour.

Sun Dogs

2007-05-24T08:41:00.001Z

I know that anybody is for the conversion of the astroclub into an astrometeoclub ;)... but I cannot resist the temptation to put here a meteo picture again... Last days the changing weather shows several amazing phenomena. The new meteo event posted here is a Sun Dog (parhelia) taken from Majadahonda during the 2007-05-19 afternoon. It is caused by the ice crystals hosted in the clouds when the light passes throught their side faces. The phenomena is very well described in this link. Here you can find also a SW to simulate the different ice halos that can be produced by the Sun depending on the size of the ice crystals.

Looking for some related info, I found a good place gathering this kind of images in the same way than the Astronomy Picture of the Day (APOD) website. Of course, it is the Earth Science Picture of the day (EPOD) website!.

I promise that the next time I will post something more "astronomical"...

Saturn Occultation 20070522

2007-05-23T13:10:00.000Z

Finally we observed a Saturn occultation. But not by the Moon... At approx. the sime time of the event (19:30 GMT) a big storm passed over this area. The following pictures were taken close the ESAC observation place.

... and more storms are forecasted for today!

A Star Formation Region?

2007-05-21T10:26:00.000Z

Unfortunatelly no. I don't know if I should be able to take an image of a similar nebula with my equipment and our usual observation place. What I know is that the weather during the last month has been uncredibly bad. And, what to do when the clouds difficult the observation of the sky?... The direct option is to observe clouds!. And this the subject of the picture. If you observe the clouded sky you can observe very amazing events. The posted image is an altered subscene of this image that I captured from Majadahonda during the May, 19th 2007 morning. It shows a fragment of an iridiscent cloud. This is a well know atmospheric optics phenomena. It is caused by water droplet diffraction in thin clouds with similar size droplets. The colours are organized into coronal rings when the droplet size is uniform across the cloud. The iridiscence is more frequently visible when part of the cloud is forming. During the cloud formation the produced droplets have a similar history and consequently a similar size. However, in other cases the clouds can be random patches or bands at the clouds edges.

In my opinion, after several years seen the atmosphere, during the last times iridiscent clouds are surprisingly frequent. I saw one twenty year ago in high mountain conditions. However during the last two years I have been able to observe several ones from different places and conditions. Can be this something related to a variation of the cloud formation patterns?... you know... Could be related to a climate warming scenario?... the debate is open.

Half Full Venus

2007-05-14T08:47:00.000Z

Shortly after the last sunset, I tried to image Venus from Majadahonda to check if something could be discriminated in the atmosphere using the filters that I have. The camera was the usual Phillips Toucam Pro with the following set of filters: a hand-made NIR filter, RGB filters and an OIII emission filter. The telescope was my Celestron 8" SCT. As Venus is still very far from us, I used a 3x Barlow to increase as possible the size of the disk in the camera detector. The following image is the obtained visible image.

As expected any atmosphere structure could be detected. The histogram can be equalized or streghtened but anything can be discriminated in the atmosphere disk. And the same happens with the other filters. Leo was very interested to check this in the NIR. The following image shows this.

However, it is well known that the Venus atmosphere presents some UV absorvers. They are distributed in atmospheric dark bands that could be constituted by chlorine or/and sulfure compounds. It is known since the Mariner 10 captured the firsts closed images of the planet. At present, Venus Express is the spacecraft observing the atmosphere in UV to better understand the composition of these bands and their paper in the atmospheric circulation. So, I tried to isolate the small UV detection range of the camera combining the IR blocking and pass filters. However, anything was observable. It could be that the IR pass filter is very restrictive in the blue part of the spectra and it extends to the UV or that at the height of the observation place the UV absortion is very high, or that the exposures were under 1 sec and perhaps is necesary to take longer exposures to detect the small UV radiation and to exploit the small detection capacity of the camera... Who knows...

Bolid from Majadahonda 2007-05-10 17:55 GMT

2007-05-11T13:50:00.000Z

Yesterday, May 1oth 2007 at 17:55 GMT, I saw a bolid over Majadahonda while I was driving to home. From the coordinates (40.4488N, 3.86732W), it appeared approx. to the SSE at a height of approx. 20 deg going to the west with a path inclination of -30 deg. Despite the daylight, it was very bright (magnitude -10?) at least during 3 seconds. During the drag its colour was clearly green and it was disrupting into small pieces. Consequently, after the friction the bolid left an irregular white smoke trail of 5-10 degrees lenght. The trail expanded and diffussed in 10-15 minutes. It was very similar to the bolid that passed over Spain during January, 4th 2004 shown in the following picture taken from the web of the Spanish Photographic Meteor Network.

Today I have been looking for some related info in the press and I didn't found any reference. I'm surprised about nobody witnessed the object. As well I have reviewed the upcoming entrys of debris and anything was expected for yesterday. Therefore, it could be probably a meteoroid.

Martian Cleaning Service

2007-04-16T10:34:00.000Z

On April, 12th 2007, I assisted at the Cosmocaixa to a conference by Steve Squyres, of the Ithace University (NY) and responsible of the Spirit and Opportunity NASA's Mars Rovers. The title of the conference was "The exploration of the Victoria Crater: The definitive probe of water in Mars". The context of the presentation was the Cosmocaixa exhibition "Mars-Earth: compared anatomy". Finally, the presentation wasn't very tecnical at all because it was addressed to the general public. However, aided with very impressive images, he described the past and present mission events and he explained very interesting things related to the engineering and operation of such type of mission. Practically all this information is in the Marsrovers JPL webpage.

One of the most interesting things he explained was related with the solar panels design and operation. It is well know that the mars surface is covered by dust that is transported by the atmosphere and deposited everywhere. Thus, as the time passes the solar pannels are gradually covered by dust. Of course, it reduces the available electrical power. At the end, the dust can cover totally the panels disabling the power supply. During the design, after the trade off of different mechanisms to clean the dust, they decided to compensate the efficiency reduction of the panels with a bigger surface. Thus, they used panels as big as possible. As a consequence, the panels should work until dust made it unusable. The designed life was estimated to be from few months to one year. But the good health of the rovers aimed a mission extension until they fail. But, as known, dust was covering everything. The following image shows this dust deposition.

And the mars winter arrived, the available sunlight was reduced and the efficiency of the solar pannels decreased by the dust... and the unexpected happened! Despite of the low pressure of the Mars atmosphere, the same meteorization phenomena that happens in the Earth as a result of the interaction of the atmosphere and the surface are present in Mars. The wind moves the dust and erode and model the surface producing sand and more dust. Thus, the same dust devils that appear in the Earth desserts are also present there. The following animation was captured by the Spirit Rover (5.7 M!).

More dust devils animations can be found in this link.

After the past of some dust devils in March, 2005, the dust on the rover was cleaned! The following pictures show the Spirit color calibration pattern and the solar pannels before and after.

And after the rover was prepared for at least another two year of power supply!

More about Saturn: The hexagon.

2007-03-29T15:27:00.000Z

The Cassiny Mission has captured a geometric feature encircling the north pole of Saturn. Unfortunatelly for SciFi fans, it is not a geometric monolith. Is is an hexagonal pattern, created by the confluence in high latitudes of atmosphere winds. The hexagon is similar to Earth's polar vortex, which has winds blowing in a circular pattern around the polar region. On Saturn, the vortex has a hexagonal rather than circular shape. The hexagon is nearly 25,000 kilometers (15,000 miles) across. Nearly four Earths could fit inside it.

The new images taken in thermal-infrared light show the hexagon extends much deeper down into the atmosphere than previously expected, some 100 kilometers (60 miles) below the cloud tops. A system of clouds lies within the hexagon. The clouds appear to be whipping around the hexagon like cars on a racetrack. The hexagon appears to have remained fixed with Saturn's rotation rate and axis since first glimpsed by Voyager 26 years ago. The actual rotation rate of Saturn is still uncertain.

Based on the new images and more information on the depth of the feature, scientists think it is not linked to Saturn's radio emissions or to auroral activity, as once contemplated, even though Saturn's northern aurora lies nearly overhead.

A full history coverage and complementary and high resolution images can be found in the Cassini webpage. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.

The Giant Planets ESAC Night

2007-03-19T15:25:00.000Z

After some periode of bad weather, skies cleared and during the nigth of March, 17th-18th we performed some pending observations. Thus, Leo Metcalfe, Eugenio Salguero and me came to ESAC equiped with our telescopes. It could be our closest oposition time to observe Saturn in good conditions. At the end it was a cold night with water&ice condensation problems but we were able to record some good images using the Leo's telescope and a Toucam Pro Webcam with NIR blocking and pass filters. The following pictures illustrate our sucessful results.

The following image is the result of the processing with Registax of a video track (20 seconds) recorded at 2007-03-18 02:13 GMT with the Leo's telescope (25" F5 Newtonian Reflector wiht Dobsonian mount), a Phillips ToucamPro Webcam with a NIR blocking filter and a 3x Barlow lens.

The next image was obtained processing a video track recorded at 2007-03-18 02:31 GMT with the same equipment but substituting the filter by a NIR pass filter.

And this image is the result of the combination of both the visible and the NIR images. This false colour combination allows a good discrimination between the different elements of the planet, the ring composed by dust and ice that reflects very well the NIR but wiht moderated absortion in the visible and the planet atmosphere that reflects well in all the wavelenghts with a some NIR absortion.

At the end of the night, Jupiter achieved a good height over the horizon to observe it in the same way. However, the seeing still was very large. As a consequence the results were not very good. The following image is a visible image obtained processing a video track recorded at 2007-03-18 05:13 GMT.

This image image is a NIR image obtained processing a video track recorded at 2007-03-18 05:17 GMT.

And this image is the result of the combination of both the visible and the NIR images. In this case, some structure is clearly visible in the planet atmosphere. The planet atmosphere reflects well in all the wavelenghts but some areas present some NIR absortion that increases the contrast between them.

Lunar Eclipse sequence from Leicester!

2007-03-06T10:17:00.000Z

Spaceweather.com posted an image sequence and a video by Darren Baskill. His comments about the eclipse were as follows:

" The changing colour of the sky during the eclipse was spectacular! From full-moon white to light-pollution red and back again in just two hours! In the photograph, each Moon is separated by just 15 minutes. The same photographs are available as a small 900kb time-lapse movie. Photo details: Canon 10D"

2007 total moon eclipse around the world

2007-03-05T21:58:00.000Z

From Germany :

From Chile :

From Jaen :

From Thailandia :

... and from Brasil :

Total Lunar Eclipse of 20070303 - VI

2007-03-05T00:17:00.000Z

Finally the eclipse party was a complete success. The night cleared and everything was as planned. Despite some tracking and connecting problems, the online webcast of the eclipse was very sucessfull too. It allowed to follow the eclipse by people from very cloudy sites. The following animation resumes the observed and webcasted event.

Total Lunar Eclipse of 20070303 - V

2007-03-03T16:31:00.001Z

Lastest NEWS (around 18:00 CET): The sky has cleared a lot. It is far from the optimal conditions but we hope it is good enought to see the moon and the eclipse. If the weather forecast finally is correct it will improve during the night. Therefore, the club confirms the star party as scheduled.

The ESAC astronomy club will also transmit on-line the event in the following link:

On-line webcast from ESAC

Total Lunar Eclipse of 20070303 - IV

2007-03-02T17:33:00.000Z

Last NEWS: At this moment (around 15:00 CET) low clouds are present at ESAC. However, the sky seems to be clearing and weather forecast is quite optimistic (see the meteo links in the right colum of the blog). Therefore, by the moment the star party schedule is maintained.

Confirmation here around 18:00 CET.

Total Lunar Eclipse of 20070303 - III

2007-03-02T17:28:00.000Z

For the moment the weather forecast for tomorrow's Total Lunar Eclipse is reasonable.

However, in case the Star Party has to be canceled this will be announced on Saturday around 15:00 CET on the ESAC Astronomy Club web page and blog.

This is the final programme:

(times in Central European Time = Local Time)
19:30 - 21:00 Arrival of people with telescopes
Parking at LAEFF only for people with telescopes
only people with heavy telescopes to drive up the SATAN hill

21:00 - 21:30 Arrival of public
Parking at the usual place close to the entrance

21:30 - 21:45 Introduction talk by Mark Kidger about the Lunar Eclipse in B.4

22:00 - 01:00 Astro Night with telescopes on the SATAN hill

Apart from the lunar eclipse (details below) we will observe many other objects like:

The Pleiades
The Double Cluster
Orion and its nebula
Saturn (the "ringplanet")
various open and globular clusters of stars
etc.

Michel G. Breitfellner
ESAC Astronomy Club President

Total Lunar Eclipse of 20070303 - II

2007-02-27T14:54:00.000Z

The ESAC Astronomy Club invites to all the ESAC community to observe a Total Lunar Eclipse on Saturday 2007-Mar-03 starting at 21:30 with an introduction by Mark Kidger in B.4 of about 15 minutes (many thanks Mark for volunteering).

Then everyone will move to the hill of the former SATAN antenna. Many thanks to Antonio Castoldi and his team who prepared the site for these kind of events with electricity for the telescopes.

These are the eclipse details compiled by Mark Kidger:

First contact with umbra : 22:30 CET, Moon's altitude 38 deg
Totality starts : 23:44 CET, Moon's altitude 49 deg
Mid-eclipse : 00:21 CET, Moon's altitude 53 deg, mag=1.24
End of totality : 00:58 CET, Moon's altitude 55 deg
Last contact with umbra : 02:12 CET, Moon's altitude 54 deg

Moon occults 59 Leonis (V=4.9) 01:42 CET (uneclipsed limb) reappearing 02:51 CET

A chart of the eclipse is in the previous post.

Weather permitting the following people will be present with their telescopes and/or binoculars:

Carlos Alfageme
Michel G. Breitfellner
Manuel Castillo
Ignacio de la Calle
Pedro Gomez
Rocio Guerra
Leo Metcalfe
Eduardo Ojero Pascual
Eugenio Salguero
Miguel Sanchez
Antonio Talavera
Carmen Morales Duran

People not listed who also want to bring their telescopes please contact Michael Breitfellner.

The following scientific projects are suggested:

Timing of contacts with umbra
First and last visibility of penumbra
Eclipse brightness estimate on Danjon scale
Timing of occultation
Estimate naked eye limiting magnitude at intervals during eclipse.
Contact timings of prominent craters with the umbra.

People interested to participate, please contact Mark Kidger! If available, hand GPS's can be very interesting for accurate time capture.

In case of "doubtful" weather the ESAC Astronomy Club will publish a GO or NO GO decision on Saturday around 15:00 CET on its web page and blog.

If you want to bring your family or friends please send a short email to ESAC security with copy to Carlos Alfageme (ESAC Astronomy Club Secretary)

Remember: At ESAC, during winter the temperature can rapidly fall past freezing in a matter of hours. Therefore it is essential to bring plenty of layers of warm clothes like when you go to the mountain. It is very important to cover your head but include thermal underwear, a parka, and gloves for the night. Dress warmly from the beginning of the evening. Once the body gets cold, it is hard to get the body temperature back to a comfortable level.

Total Lunar Eclipse of 20070303 - I

2007-02-20T16:04:00.000Z

Weather permitting, it could be the next club observation meeting. As the Satan site has been conditioned, it could be celebrated with the first night party of the year as an open activity. So prepare your Lidlscope, or another equipment if you prefer it, and come here to enjoy the eclipse. Still it will be possible to observe Saturn near the oposition (see the dedicated post). Date approaching, weather forecast will be posted here.

Diagram courtesy of F. Espenak, GSFC-NASA

Themis Launch Today

2007-02-15T08:48:00.000Z

THEMIS Launch is finally set for today. The mission webpage is in http://www.nasa.gov/mission_pages/themis/main/index.html. NASA'S THEMIS (Time History of Events and Macroscale Interactions during Substorms) is a 2-year mission consisting of 5 identical probes that will study the violent colorful eruptions of Auroras. It aims to resolve one of the oldest mysteries in space physics, namely to determine what physical process in near-Earth space initiates the violent eruptions of the aurora that occur during substorms in the Earth's magnetosphere.

To "compensate" the THEMIS media impact, ESA describes some results of CLUSTER relative to the Auroras in the ESA's webpage.

Well... it seems that this post is out of the scope of this webpage... or not?... From the point of view of the amateur observational astronomy, auroras are good targets to observe. Of course, if you are in the correct place!. As a sample, I post here a video of Auroras that I filmed in Iceland during September, 2003 with a digital video camera in NIR. It is mounted as a new age music videoclip... so... enjoy it!

Saturn Opposition 2007

2007-02-14T09:54:00.000Z

Saturn is now in its period of apparent retrograde motion and achieved Opposition relative to the Sun on FEB 10 at 15 hr UT and its closest approach to Earth of 8.20035 AU.

Around the time of Opposition, Saturn is rising near sunset, transiting the southern meridian around local midnight, and setting near sunrise. Threfore, it is the most favourable moment to observe it. Its ecliptical latitude was N 1.3°, and its declination N 15.5°. That means for northern hemisphere observers, at meridian transit Saturn culminates at an altitude that is equivalent to one's co-latitude (90° minus one's geographic latitude) plus 15.5°.

At Opposition, Saturn's apparent equatorial angular diameter was 20.2 arcseconds and its rings covered 45.8 arcseconds. Its axial tilt relative to Earth was -13.9°. That means we will still be viewing the southern side of its rings, which orbit above its equator. The tilt will reach its extreme of -15.4° for this synodic cycle on APR 18. The extreme tilt for its 29.5-year orbital cycle came in 2003 at -27.0°. The rings will seem to disappear around the period when Earth moves through Saturn's equatorial/ring plane on 2009 SEP 04.

The previous section was taken from http://www.astronomy.com/ASY/CS/forums/325356/ShowPost.aspx and the next section from http://www.spaceweather.com

Observers who point a backyard telescope at Saturn (highly recommended) may notice that it doesn't look the same as it did last year. "The rings are tilting toward Earth," says amateur astronomer Alan Friedman of Buffalo, New York. He has been photographing Saturn for years and made this movie of his observations between 2004 and 2007:

"The Slow Dance of Saturn" by Alan Friedman using a 10-inch telescope.

The changing aspect is due to a combination of geometric factors, mainly the tilt of Saturn's spin axis plus the orbital motion of Earth. Eventually, the rings will narrow so much that they briefly disappear before opening up again. The next ring plane crossing: Sept. 4, 2009. Meanwhile, the rings are uncovering Saturn's blue north pole--one more reason to look through a telescope this time.

Moon Travel 2006

2007-02-13T11:39:00.000Z

In order to feet the creature, I include here a new astromovie. It shows a travel over the Moon with the Leo's 25" telescope & a ToucamWebCam Pro with a NIR pass filter. The video was taken from ESAC during the night of October, 14th 2006.

Invitation to Contribute

2007-02-13T11:34:00.000Z

I have sent an invitation to all the members of the ESAC astronomy club, I think..., Please, follow the instructions and after you will be able to introduce new post and comments. As mentioned in the first blog post, practical contributions are wellcome about astronomical events, updated ephemerids, weather forecasts, practical information about equipment, your observations, discussion topics (eg. light pollution), infrastructure news (eg. Satan site) and everything you think that could be interesting and/or useful.

Simulated Light pollution map of Spain.

2007-02-09T15:48:00.000Z

Find here the link to an interactive & dynamic light polution map of Spain. It has been simulated by the French AVEX organisation. They use different cartographic layers (population, topography, land use, infrastructures, etc) to estimate the light pollution affecting the different areas of the territory.

The associated color legend is as follows:

White : 0-15 visible stars (without planets) according to the conditions. Very high level of light pollution and all around. Typical of big urban centre and big regional and national cities.
Magenta : 25-80 visible stars. Principles constellations began to be recognizable.
Red : 80-150 stars : constellations and others stars appears. In a telescope, Some Messier object began to be observable.
Orange : 150-250 stars in good conditions. The light pollution is present all around but some darks areas appears. Typicaly the middle suburbs.
Yellow : 250-500 stars. Strong light pollution but the Milky Way can appear in good conditions. Some Messiers among the most bright can be visible with the necked eye.
Green : 500-1000 stars : far peacefull suburbs, Milky Way many times visible but very sensitive to the atmospheric conditions. Typicaly, the glare of light pollution take a large place in the sky and reach at 40-50° of elevation.
Cyan : 1000-1500 stars. The Milky Way is visible most of the time in fonction of climatic conditions but without contrast.
Blue : 1500-2000 stars. Good sky. The Milky Way is easily visible, we began to have the sensation of a good sky, but, some source of light pollution damage the sky and in a second time the sky by reflexion at the vertical of the observer.
Night blue : 2000-3000 stars. Very good sky. The Milky Way is present and powerfull. The light glares are far away and scaterred, they don't affect the sky quality.
Black (gree by texture transparency) : more than 3000 stars. No light pollution problems revealable on the sky quality

The following picture shows in detail de area around ESAC.

The advantadge of the simulation is that the spatial resolution that can be achieved depends on the resolution of the used cartographic base. Direct estimations of light pollution are based in the direct measurements of the DMSP satellites . But in this case the best achieved obtained resolution is around 10 km.

1920's Astronomy Amateur Movie

2007-02-09T11:40:00.000Z

In order to inaugurate the blog, find here an amateur 1920's movie explaining some astronomy concepts.

Source: Prelinger Archives at The Library of Congres - USA. On-line in the Internet Archive

Welcome to the ESAC Astro Blog

2007-02-09T09:09:00.000Z

Following the success of the ESAC photo club blog, I have started a similar blog for the astronomy club. I think it can be useful to dynamize the activities of the club. Thus, practical contributions are wellcome about astronomical events, updated ephemerids, weather forecasts, practical information about equipment, last observations, discussion topics (eg. light pollution), infrastructure news (eg. Satan site) and everything you think that could be interesting and/or useful.

I will set everything up so club members can create entries in the blog. If you want to respond to any entry please use the 'comments' functionality don't create another entry. Thus, it could be a useful tool better than the usual e-mail chain.

Manuel