ISS transits the Sun

This white-light image shows the International Space Station transiting the Sun on 20 April 2013, at 17h 35min 32sec. It was captured from the Valmayor reservoir, in Valdemorillo, Madrid, Spain. The active sunspot group number 1726 is visible in the center of the image.

ISS crossing the Sun: frame stacking

The ISS crossed the limb of the Sun in ~1.2sec. The image was taken with a Canon EOS 500 in video mode (25fps, full HD) through a Messier R102 Optical tube with a Baader solar filter. A Coronado SolarMaxII 90 BF30, in piggyback, also recorded the transit. H-alpha images are still being processed.

ISS transit, movie in normal speed

ISS transit, movie in 4x slow motion

The observing team

2013-12-18: A new observation of the PanSTARRS Comet

The following figure shows together two observations of the comet on 2013-03-14 and 2013-03-18: 4 and 8 days after its perihelion pass. As this non-periodic comet is moving away from the Sun, in the images it can be observed that the cometary activity is being reduced. The nucleus, coma and tail glowing are fading as it can be seen in the visible and false colour images.

The third column of images show the image after application of a Larsen-Sekanina filter (Sekanina Z., Larson S. M., 1984. The Astronomical Journal 89,571.). It is a rotational gradient filter that allows to observe fine morphological structures around the comet. So, the morphological changes in the nucleus, the coma and the tail become quite evident. Although there is also a change in perspective as the coment is moving away, comparing the images it can be observed an activity reduction in the extension and density of the tail, the size of the coma and the fine jets emerging for the nucleus.

Comet Pan-STARRS (C/2011 L4) captured from Majadahonda on 2013-03-18 from Manuel Castillo Fraile on Vimeo.

2013-03-14: Pan-STARRS Comet from Madrid

Today, as in the previous days, the cloud coverage in Madrid difficulted seriously the observation of the comet. However, few holes opened at last time allowing to capture few pictures of the comet.

The following picture has been generated stacking 15 images captured on 2013-03-14T19:14 UTC with a DSLR Canon EOS 60Da through a 20 cm SCT.

The same picture shown in HDR shows very well the nucleus of the comet together with the dust tail and other glowing structures.

2013-03-12: First look to the Pas-STARRS Comet from ESAC

Although the weather was incredibly bad, few moments before the comet went below the horizon, the sky opened a small window and I "catched it". The following image is a stack of 10 pictures of the comet.

 

 The following image has been produced  stacking 10 pictures of the comet.

The sequence of images is in this video:

2013-02-15: 2012 DA4 Observation from ESAC

Last Friday, 7 of us with few guests met at ESAC to observe the closest approach of the asteroid 2012 DA4. Although the clouds, together with the light polution, endangered the observation at the beginning of the night, during the event the weather was good enough to observe and image the asteroid. Finally we mounted the Wouter 12 inch Dobsonian and the Michel 8 inch Newtonian.  In order to record the event, instead of the telescope of the club, we mounted the ESAC Photo club 400 mm TeleLens (thanks!!!) together with a Canon 60Da DSLR in a CG5 Celstron mount for the sideral tracking. After use this TeleLens, I cannot assess the general conclusion stated in the last post. So, at least this one allows a field flattening good enough for astronomy. The following video is a time lapse movie of the party in the top of U building.

Thanks to Wouter Van Reeven, we were able to see the asteroid from the beginning of the night. We must recognize that without his observational ability with his 12 inch Dobsonian the success of the observation was seriously compromised. Really it was complicated to observe the event.  He showed us how to use SkySafari in a iPad to guide the observation and he also provided the sky maps with the track that allowed to record the asteroid pass in the area of Ursa Major. The following video shows the track in this area when the asteroid was moving away from the Earth..

In order to better appreciate the track, it is recommended to see the video in youtube at the maximum resolution (HD1080). The following sky map was produced by Wouter to show the apparent track as seen from ESAC. The purple square indicates the area shown in the video.

2012-06-24: Andromeda Galaxy (M31)

Last Saturday I captured this image of the Andromeda Galaxy (M31) from Boada, Salamanca, Spain. The equipment used was a Canon 550D, a 200mm SIGMA APO teleobjective with an exposure of 60 secs at ISO 12500. The Celestron CG5 mount was used to perform the tracking.

The used teleobjective is apochromatic and it is quite convenient for astrophotography.  However, I have discovered that the field is not flat enough. Although I cropped the image the distortion is clear. As Miguel commented,  it is an empirical assessment about something that astronomers knew long time ago: you must use a telescope, i.e. a large optical length to achieve a flat field close to the axis.... It has been sacrificed in standard photography... so, forget to use all the photographic stuff for astro!!!!!

2012-06-09: Australian Skies

During the australian tour after the Venus transit observation in Canberra, Miguel Sanchez-Portal and me captured the following images of the southern winter sky in Australia. The images were obtained somewhere in the road near to Barthust, New South Wales, with a  Canon550D with ISO forced mode, full aperture and 15 seconds of exposure.

Southern Area of Scorpio

Southern Cross and Alpha Centauri

Magellanic Clouds

So, it is quite evident that light pollution is nearly inexistent in Australia.