ASTRO: NGC1931 with OSC camera

I recently used my ASI1600MC cool colour camera for the first time "seriously" for long exposures on my 10" Meade ACF (have tried some "lucky imaging" before).
NGC 1931 was the chosen target. Unfortunately seeing was bad and gusty wind knocked the guiding star out of position frequently. Even scaled down to 0.9 arcseconds/pixel stars look bloated. I probably should have utilised the ability of the ASI1600 cameras for short subexposures to get better sharpness.
I also lost 1.5 hours around culmination because I was not aware that my new bluetooth power adapter distinguishes between weekdays and weekends and shut down at midnight because I had not set a schedule for weekends.

Taken from Berlin with a 10" Meade ACF on a G11 mount, ASI1600MC cool camera at unity gain, 81x5 minutes.

Stefan

My 2008 image of it shows even more bloated stars though was taken at 1" per pixel. Also my limited processing abilities back then bloated stars when stretching more than I do today as I didn't hide them from the full stretch nor apply PS add-ons like Star Shrink and other techniques I've learned since then. What I really notice however is the very faint outer parts that show as red or red-orange in your image come out blue in mine. Yet star colors match rather closely. My camera is far more blue sensitive than red sensitive so doesn't see as deeply in red. I've not looked up the curves for your OSC camera. Thought it was taking some flack for not being all that great at Ha but has to beat mine I'd think. I've attached a 1.5" per pixel crop showing what I mean.

As I explained I had to take a hiatus from imaging. Last night was the first sort of usable night. Good seeing with FWHM down about 1.5" which is rare here but transparency was poor due to high clouds from a snow storm forecast for later today. Due to 3 months layoff I expected a goof or two. Sure enough I couldn't get the software to see the observatory. I lost a half hour imaging time, and I started an hour before it was dark enough, before I found the problem. Every time I shut the observatory roof I cut power to everything but the roof and lights if I go in with the roof shut. So the very first thing I do when imaging is going to happen that night is turn on the power switch then turn on the computer and fire up the script file for that evening that does all the work while I'm doing something else. Somehow I never threw that switch so of course the connection to the observatory was dead. I wasted good imaging time before clouds because I forgot step one. Never did that before. Everything else worked fine after that but for clouds hurting the second and third targets. May need to redo them but with such good seeing I may just go with the limited data the clouds allowed.

Rick

Originally Posted by slilge

I recently used my ASI1600MC cool colour camera for the first time "seriously" for long exposures on my 10" Meade ACF (have tried some "lucky imaging" before).
NGC 1931 was the chosen target. Unfortunately seeing was bad and gusty wind knocked the guiding star out of position frequently. Even scaled down to 0.9 arcseconds/pixel stars look bloated. I probably should have utilised the ability of the ASI1600 cameras for short subexposures to get better sharpness.
I also lost 1.5 hours around culmination because I was not aware that my new bluetooth power adapter distinguishes between weekdays and weekends and shut down at midnight because I had not set a schedule for weekends.

Taken from Berlin with a 10" Meade ACF on a G11 mount, ASI1600MC cool camera at unity gain, 81x5 minutes.

Stefan

Rick,

I forgot to mention that most of the data (except for one hour) was taken through an Astronomik CLS filter, which attenuates the reflection part compared with Halpha and generally shifts colour a bit.
Or maybe I simply didn't capture the faint reflection parts.

Good to hear that you are imaging again.

Stefan

I was imaging. Got 6 in December then an ice storm hit. We never get winter ice storms. But this one hit anyway coating everything with 2" of ice. Then winter temperatures returned. Been -35C to -19C since so no thaw. It froze my roof in a thick layer of ice. With the roof over 5 meters in the air I have no way of thawing it. No way I can get on a ladder with that ice layer. Any ladder tall enough would just slide away. We never get above 0C until late March or early April and then only for short periods mid afternoon. I might be frozen until April.

Folks that have lived here for 50 years can't recall ice like this in winter (hit Christmas day so was my Christmas present from you know where.

Rick

Originally Posted by slilge

Rick,

I forgot to mention that most of the data (except for one hour) was taken through an Astronomik CLS filter, which attenuates the reflection part compared with Halpha and generally shifts colour a bit.
Or maybe I simply didn't capture the faint reflection parts.

Good to hear that you are imaging again.

Stefan

Originally Posted by WA0CKY

... might be frozen until April.

No such problems here, we just had the first three days of snow this winter and it will only last 2-3 more days. We don't seem to get real winters any more.

Stefan

Our last two winters were nearly snow free and unusually warm. This one started that way but everything changed with the ice storm. Lack of snow for two years means many wetlands are drying up as they depend on lots of snow for much of their water supply. The swamp behind my place used to be about knee deep but last summer was ankle deep at best and sometimes just mud. Mud is good for mosquito control but bad for wildlife that depended on the water.

Also over the 60 years I've been coming here I've watched the fir forest that was thick 70 km south of me die back and mostly vanish. The fir line is just about where I am now. I lose 4 or 5 firs a year so the line is moving north with our idiot president elect's "non existent" climate change.

Rick

Originally Posted by slilge

No such problems here, we just had the first three days of snow this winter and it will only last 2-3 more days. We don't seem to get real winters any more.

Stefan