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Posts Made By: Dave Mitsky

June 25, 2009 03:49 AM Forum: LUNATICS

June New Moon Spotting

Posted By Dave Mitsky
I beheld the thin crescent Moon while I was driving to a dark site on Tuesday evening.

Dave Mitsky

July 16, 2009 06:37 PM Forum: SCI-FI

One Second Later

Posted By Dave Mitsky
Remember what Snake Plisskin did at the end of Escape from L.A.?

http://www.moria.co.nz/index.php?option=com_content&task=view&id=1321Itemid=1

Dave Mitsky

July 23, 2009 08:15 PM Forum: Refractors

True APO ??

Posted By Dave Mitsky
To muddy the waters further, here's what Al Nagler had to say on the subject some years ago on the now defunct Ask Al section of the Tele Vue site:

Phil Barker asks about descriptions or standards regarding color
correction in refractors.

This is a complex issue, Phil. The residual color can be altered by
design, by manufacture and even by the individual "melt" production in
glass. Spherical aberration also varies with color (spherochromatism).
Then there's the matter of how much residual color is visible and the
nature of the hue. There are "classic" definitions for standard
achromats, but considering fluorite and other exotic doublets, triplets,
and 4-element systems, there's lots of wiggle room on APO definition. I
consider a system an APO when there's little or no color fringing on a
bright star at 200x, and semi-apo when performance is significantly
better than an achromat for a given focal ratio. Earned reputations are
indeed your best guideline at this point.

August 1, 2009 05:55 PM Forum: SCI-FI

Warehouse 13

Posted By Dave Mitsky
Warehouse 13 is quite derivative but has been worth watching so far. I also enjoy Eureka.

Dave Mitsky

August 2, 2009 03:25 AM Forum: Solar System Observing

A new small spot on Jupiter??

Posted By Dave Mitsky
Perhaps it was Jupiter's third red spot...

http://www.newscientist.com/article/dn13963-third-red-spot-erupts-on-jupiter.html

Dave Mitsky

August 20, 2009 03:03 PM Forum: After Dark

Dark sites to go to without being harassed...

Posted By Dave Mitsky
A few observing sites located in Ohio are listed at http://www.observingsites.com/ds_oh.htm

Dave Mitsky

August 20, 2009 06:36 PM Forum: Eyepieces

GREEN DEATH: Ethos 21mm is here!

Posted By Dave Mitsky
At this year's Stellafane, I had a chance to look through the 21mm Tele Vue Ethos prototype on Friday night. Al Nagler was showing it off in Sky & Telescope columnist Sue French's 130mm f/6.3 Astro-Physics Gran Turismo refractor. We looked at NGC 7000 (the North America Nebula), NGC 6992 (the eastern portion of the Veil Nebula), M8 and M20, M31, and the Double Cluster. The Double Cluster was especially stunning.

On Saturday night, I once again had the opportunity to use the 21mm Ethos. This time one of the prototypes was in a 28" StarStructure Dob on the lower field and the other was atop Breezy Hill in a 28" f/3.6 ATM Dob that was entered in the telescope competititon. Both scopes were trained on M27. Later on, I saw a number of other DSOs including M11 through the 28" f/3.6 Dob and the 21mm Ethos.

The 21mm Ethos has almost the same true field of view as does a 26mm Nagler Type 5 and provided some excellent views.

Dave Mitsky

September 3, 2009 02:32 AM Forum: Solar System Observing

Have a Look at Jupiter Tonight

Posted By Dave Mitsky
Here's the sequence of satellite events from the S & T page:

Wednesday, September 2, 2009

23:28 UT, Callisto enters occultation behind Jupiter.

Thursday, September 3, 2009

03:44 UT, Io enters occultation behind Jupiter.
04:00 UT, Europa begins transit of Jupiter.
04:46 UT, Ganymede begins transit of Jupiter.
04:56 UT, Europa's shadow begins to cross Jupiter.
06:32 UT, Io exits eclipse by Jupiter's shadow.
06:46 UT, Ganymede's shadow begins to cross Jupiter.
06:50 UT, Europa ends transit of Jupiter.
07:50 UT, Europa's shadow leaves Jupiter's disk.
08:24 UT, Ganymede ends transit of Jupiter.
08:44 UT, Callisto exits eclipse by Jupiter's shadow.
10:24 UT, Ganymede's shadow leaves Jupiter's disk.

Dave Mitsky

September 24, 2009 04:59 PM Forum: Star Parties

Black Forest Star Party 2009

Posted By Dave Mitsky
Dr. Elliott McKinley, Heidi, and his 20" Obsession...

September 24, 2009 05:04 PM Forum: Star Parties

Black Forest Star Party 2009

Posted By Dave Mitsky
John Vogt and his wonderful 32" ATM Dob...

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