Astrofiles
Auburn Astronomical Society E-Newsletter
December, 2006

In this Issue


December Events Upcoming Events
Transit of Mercury Member News
Short Subjects Loaner Scopes
Astronomical Primer  

December Events

This monthís meeting will be on Friday, December 1, at 8:00PM in room 215 of the Aerospace Engineering Building

Riders from the Montgomery area are welcome to meet at the home of Russell Whigham, 518 Seminole Dr.,  and carpool over to Auburn.  Plan to be ready to leave for Auburn at 7:00PM. 

Our dark-sky star party this month will be on Saturday, December 16, at Cliff Hillís farm,  clouds permitting of course. 

Upcoming Events

December 1, December meeting
December 3, Lunar occultation of the Pleiades
December 4, Earliest end of evening twilight
December 7, Earliest sunset
December 16, December star party at Cliff Hillís farm
December 21, Winter Solstice --  shortest  day
January 5, January meeting
January 13, January star party at Cliff Hillís farm
April 19-22, Georgia Sky View 2007 

    Transit of Mercury
Glynn Alexander called to report several hours of successful observation of the transit.  Your editor took his filtered ST80 to work, hoping to steal a glance as time permitted.  Alas, time did not permit use of the scope.  When I stepped outside with only the solar ďSunĒ glasses, I suddenly realized how egregiously I had over estimated the size of Mercuryís disk against the Sun. 

Scott Thompson hurried home from work and barely caught the event as the Sun slid into the trees.  Here is Scott's image of the transit of Mercury.

Member News

Robert Rock called to explain why he has missed attending recent AAS meetings.  Robert is engaged to be married and has been distracted lately.  Congratulations, Robert!

Short Subjects

For Sale:  Celestron C-8. Robert Rock

Free to a good home: 10 years worth of Astronomy magazines. Scott Thompson

Meade Sale on some new telescopes:   Syd Spain

"Astrological" Telescope

I found us a new dark sky site.  It will be a long drive but imagine the views. Shane Bledsoe
http://www.globalsecurity.org/wmd/world/dprk/images/dprk-dmsp-dark-old.jpg
Star drift method for polar alignment for equatorial mounts:
http://www.darkskyimages.com/gpolar.html
Man is the best computer we can put aboard a spacecraft and the only one that can be mass produced with unskilled labor. -Wernher von Braun, (1912-1977)

Loaner Scopes

Let Loaner Scope steward, Rhon Jenkins, know if you (members only) would like to have your name added to the list to borrow either of the loaner telescopes. 

Astronomical Primer

Q.  Can someone explain why a long exposure photograph will show more detail than when looking through a scope? 

A.  The scope's diameter is much larger than your eye's pupil diameter.   In the ratio of (200 mm/6 mm)^2  = 1,100.  That's a lot more light.   That's 7.6 magnitudes gain due to aperture. This is called optical  gain.  Your eye takes "pictures " with an equivalent exposure time of 1/15 second. An imager typically exposes for one hour.  The gain in signal is thus (3600/1/15) = 54,000. That's 11.8 magnitudes fainter than you can see with your eye through the eyepiece.

Dennis Persyk
Igloo Observatory Home Page http://dpersyk.home.att.net
 

Hoping to see everyone at the meeting and the star party,

Russell