From: "milton_aupperle" <milton@outcastsoft.com>

Date: September 25, 2012 9:52:07 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: HATP10/WASP11b Exoplanet transit

Hi Ron;

Thanks.

My problems is how variable the seeing can be over very short time period here. If the turbulence and seeing is consistent (even bad seeing but consistent) then you get better results.

The night I images HAT-P-10/WASP11b (H10W11b for short), I achieved sharp focus easily on a star in Andromeda and had a measured FWHM in the 3 to 4 arc second range. Then I started the cooler up as I waited for H10W11b to clear the condo wall to my east. I checked the camera 20 minutes later and the star I focussed on is a big fuzzy ball. I was sure it was condensation on the CCD (humidity was 30% then) , so I let the camera warm up to 25°C again. It made no difference at all. So I decided to re-focus the AT8 RC Scope in case I pooched that when tightening the focus lock knobs, but I could not achieve sharp focus because the star was shifting so much (at 15 or higher fps I could see the jitter but not at 7.5fps) - the Live FWHM /HFD display was showing 6 to 9 arc seconds for FWHM. 10 minutes before H10W11b cleared the condo wall, the skies dropped down to 2 to 3 arc seconds for FWHM - but in looking at some of the 800 frames of vide collected, you can see the stars literally disappear due to turbulence.

HTH..

Milton Aupperle

--- In Astro_IIDC@yahoogroups.com, "cosmicrock2001" <ursamajor_1@...> wrote:

Thanks for posting this, and showing it can be done with poor seeing!    Ron