Tuesday, 27 February 2007

Total Lunar Eclipse of 20070303 - II

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.

Tuesday, 20 February 2007

Total Lunar Eclipse of 20070303 - I

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

Thursday, 15 February 2007

Themis Launch Today

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!

Wednesday, 14 February 2007

Saturn Opposition 2007

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.

Tuesday, 13 February 2007

Moon Travel 2006

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

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.

Friday, 9 February 2007

Simulated Light pollution map of Spain.

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

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

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.