Thursday, January 29, 2009
The comet's orbit is in nearly the same plane as Earth's but is traveling in the opposite direction. This causes Lulin to appear to move unusually fast and display a rare anti-tail—an optical effect that creates a secondary "tail" pointing toward the sun.
Pictures from non light polluted sites already showing Lulin's rare anti-tail.
As seen from Griffith Observatory tomsastroblog.com/?p=2760#
More can be found on Google www.google.com/search?sa=N&tab=nw&q=Comet%20Lulin
This image is a stack (using Deep Sky Stacker ( DSS )) of nine 47 second exposures, ISO 800. My location is light polluted Los Angeles city.
exposures using a Canon 75-300mm lens at 300mm.
Friday, January 16, 2009
also at http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/2866027/Main/2866027
Taken with 530mm lens at f7 on 1/16/09
Wednesday, January 14, 2009
Saturday, January 10, 2009
"Web Beacons" to track every Yahoo Group user. It's similar to
cookies, but allows Yahoo to record every website and every group you
visit, even when you're not connected to Yahoo. Look at their updated
privacy statement at: Privacy
About half-way down the page, in the section on *cookies*, you will
see a link that says *WEB BEACONS*. Click on the phrase "Web Beacons."
On the page that opens, on the left find a box entitled "Opt-Out." In
that section find "opt-out of interest-matched advertising" link that
will let you "opt-out" of their snooping. Click it and then click the
opt-out button on the next page. Note that Yahoo's invasion of your
privacy - and your ability to opt-out of it - is not user-specific. It
is MACHINE specific. That means you will have to opt-out on every
computer (and browser) you use.
Friday, January 09, 2009
I'm thinking of making the ultimate user friendly telescope, fixed eyepiece and capable of having the observer in a warmed room.
It's amazing how close the final picture below is to my idea, goes to show how few ideas are really new.
Drawing fodder is below.
Optical layout of a Celestron Schmidt-Cassegrain Telescope. A mirror will be placed near the center of gravity, directing the light path out the side, like the blue drawing below.
Below from http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Board/atm/Number/856685/page/2/view/collapsed/sb/7/o/all/fpart/3
"What I was looking at was an exact replica of the famous "Springfield Telescope" built by a gentleman who was a retired machinist. I handed him some money and asked that he send me a copy of Porter's original "blueprint". He did and I set about to model the device in one of today's more respected 3D solid modeling softwares: SolidWorks. - Art Bianconi Member # 15558
Total Posts 4659 Homepage http://www.vortexgenerator.net Occupation Mechanical Designer/Engineer
(from edhiker) The project is to use a optical layout about like the above, but use a 8 to14 inch Schmidt-Cassegrain Telescope mounted as a Springfield.
Book - Unusual Telescopes By Peter L. Manly, pictures below from the book.
Notes which document taking apart a C11 = http://www.rothritter.com/C11_Project/