Chuck: My experience with large mirrors is that waiting an hour works better than a fan. I just spend the time walking around talking to others and looking through their telescopes. I'm also trying to come up with a good picture that represents the event well. I put my camera on a monopod and hold it up in the air for a longer perspective of the entire ground. The only problem seems to be that people want to look up and point at the camera. http://www.slas.us/gallery2/main.php?g2_itemId=3428 DT --- On Sun, 5/16/10, Chuck Hards <chuck.hards@gmail.com> wrote:
From: Chuck Hards <chuck.hards@gmail.com> Subject: Re: [Utah-astronomy] Thank you on Ealing upgrades and repairs To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Date: Sunday, May 16, 2010, 3:37 PM Daniel, if you are interested in adding a fan(s) to blow across the front of your mirror, I would be willing to help.
Per Bryan Greer's breakthrough article in S&T some years ago, and verified by Alan Adler, where he proved that breaking-up the air currents above the mirror's surface is more important than cooling the mirror to ambient temperature, I would love to help engineer and fabricate such a simple system for your (or anybody's) reflector.
The results are remarkable. I use a modified version of this on my 6" Newtonian and you can see instant results as soon as you flip the fan switch on. Hours before the mirror itself has cooled.
Increased aperture is always better, as long as you arent' hobbled by other factors.
On 5/16/10, daniel turner <outwest112@yahoo.com> wrote:
Chuck:
On Friday night I took Alan MacRoberts article in S&T with me to SPOC. Using the chart for the elongations of Mimas I was able to see the see this tiny moon next to the glow of the nearly edge on rings. I was using 17.5 inches of aperture and I needed to wait for the mirror to cool down and then had to catch a moment of excellent seeing in the variable seeing of the night. Alan and others have seen this with 12 inches of aperture. Now I'll be looking for Iapetus and Hyperion which are supposed to be easier.
On Friday and Saturday I picked up two comets. The transparency wasn't very good on either night but these still came through as easily as a Messier eliptical galaxy.
_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com