From: Mark Gaffney <markgaffney@me.com>

Date: October 2, 2010 7:39:36 AM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Images from last night


Milton, 

I have looked at & taken note of your guide star movie. 

I`ve tried re-doing my 2 star alignment + 4 star calibration more than twice & finally got as far as the 2 alignment + 2 extra calibration stars (finished..!) two nights ago. 

I`ve had troubles with a visitors`s car here being parked behind my scope & running over my leads causing a loose connection.. but mostly with the weather. 

They predicted a wet Spring on the National TV network & so far they`ve been right...

I often look out & see a clear sky but some sort of clouds usually ruin my complete 6 stars alignment/ calibration before I`m finished. 

I understand there`s away of using the HC so you can save the setting for an added calibration star already committed to & by not moving the scope you can return to it later. Trouble is circumstances haven`t conspired for this yet.. so I`ve just done the best I can! 

Consequently I haven`t returned to test guiding on a real star of any description..


Mark. 

On 02/10/2010, at 4:58 AM, milton_aupperle wrote:

Hi Folks;

We had clear dark (Mag 4 visual) skies last night, with both "Clear Sky Clock" and NAM forecast predicting low turbulence (basically wrong). I ignored Jupiter (won't be above 30° until 12:30 pm anyhow) and went after some DSO's as it gets dark here by 8:30 pm.

I shot LRGB for NGC 6995 (which is the souther portion of the Veil East nebula in Cygnus) but have only quick processed the Luma in this image:

http://tech.groups.yahoo.com/group/Astro_IIDC/files/DSO/VeilsEast_NGC6995_20100930.jpg

I only captured Luma for NGC 206 (open cluster in the west / south arm of M31) and then just gave up for the night due to turbulence.

http://tech.groups.yahoo.com/group/Astro_IIDC/files/DSO/M31_NGC206_20101001.jpg

The turbulence was really really erratic. I would get these brief sporadic "turbulence" events where the guide star would be jerked about so fast it would literally disappear for 3 to 20 seconds, then reappear for 3 seconds and then jump 20 arc second in any direction. Then it would go calm and the guiding graph would be nearly completely flat. This low frame rate (0.8 fps) mp4 movie:

http://tech.groups.yahoo.com/group/Astro_IIDC/files/Other/M31_NGC206_GuideStar.mp4

shows what a Mag 7.2 star looks like during one of these events. The guide star shown in the last frame of the mp4 movie is about 1/2 as bright as it appears when there was no appreciable turbulence. Except where the star disappeared, Astro IIDC would locate and chase the star just fine.

Have a great weekend..

Milton Aupperle