Until at least 1630 today, there was a patch of average seeing in the Astrospheric forecast lasting a couple of hours centered around midnight, and I decided to take advantage of it by setting up for imaging Mars and the Moon.
My setup was the G11/Meade, to which I added the planetary imaging setup, because I was imaging Mars first. I did not check polar alignment, and FC autoguiding was able to keep up with the drift. I believe that my PA has been left unchecked/not adjusted for about a month!
I focused on Mars using the eyeball method, then went to Aldebaran for a star-first focus with the mask. I found that my eyeball focus on Mars was pretty close.
I went out to do a preliminary capture on Mars just as it came out of the trees at 2030, at which time I was expecting the seeing to be below average. The idea behind this capture was to have something to show for my work if weather, scope, computer, or me suddenly went south.
The temperature was 35 degrees. The NWS was forecasting the dew point to hug the temperature plot all night long, so I was expecting dew early, and maybe frost later.
I acquired Mars, set a 320 x 320 ROI, which is a little larger than normal to account for poor seeing, started autoguiding, and went inside until I went back outside for just a few minutes to switch to the ASI178 for shooting the moon. Mars stayed within the ROI from 2030 until I left it at 2315.
I used my recently adopted declining histogram method, capturing 3 runs of IR and RGB. IR, R and G were 45s and B was 60s. The seeing on the display looked below average or worse. I decided to wait to do another capture as Mars culminates, hoping that the thinner cross section would permit less seeing distortion. Seeing only worsened while I was waiting, so I abandoned that project.
My hope was if I had captured the two images, one captured at 50 degrees elevation and the other at 75 degrees elevation, I could have given me a sense of how much of a factor that elevation is in making a good image.
I switched over to the moon at 2315, and then went outside to change cameras. By this time it was 31 degrees but there was no frost or dew on anything. RH was 86%.
Seeing on the Moon looked really bad, even with the 2.5x PowerMate removed from the path. I made maybe three or four captures and gave it up at 2345. The temperature was 30 degrees and there was no frost on anything.
As an aside, tonight I was treated to a change of scenery from the view of Mars that has dominated my last few sessions. I could see the area immediately preceding Syrtis Major, which was center on longitude 171 degrees. When I first started imaging Mars, I was hoping to catch Syrtis Major (longitude 285 degrees), Mars’ most prominent albedo feature, but it seemed that it was always facing away from Earth. After I was finally able to catch view of Syrtis Major, it seemed to dominate my next several sessions.
This was my second time with the small laptop as a remote computer, and it worked flawlessly. I have had doubts about sub-30’s weather in the field, but with the minimal time that I need to spend outside, I am beginning to wonder if I can do it. A thought that I am letting develop as I transition to DSO is to do a colder weather (30 or below) check here at home where I can easily abandon the silliness if I get in over my head. More thoughts to come.
The poorer than expected seeing was a disappointment, but tonight was a good practice run, and it was great to see everything working as it should.
Thinking in a forward direction, I want to test the DSO setup with the small laptop as the remote computer. I cannot think of any reason why this will not work. After testing that setup, and doing a trial run with the GM8/TV to see if autoguiding is sufficient for imaging, I am thinking about buying a cover for it, and going ahead and setting it up.