Bumps on the imaging highway; more (unfinished) images

This is astrophotography, so things are never as easy as one hopes. 

At the beginning of September I had an all-night imaging session at the club's Eagle Lake Observatory site.  I was trying to do a few targets: M31, The California Nebula, and because a little time was left over as the dawn was approaching M42. Let's start with the latter because it illustrates the main issue.

I had only about a half an hour before the morning sky started to really brighten, so I set up NINA to do five 90-second frames for each LRGB channel. Here is the initial stretched result:

 

 

I did say LRGB, but this is mono! It turned out I took 20 L frames; the mystery is how that happened. I wish I could tell you, but I don't know the actual cause. My best guess is that NINA lost contact with the filter wheel and couldn't execute the filter changes. So this is not quite the image I wanted, but eventually I'll be able to shoot the chroma and make a nice image.

 

The same thing happened with my California Nebula frames and I've got 96 L frames which should make for a really nice eventual image. Here's a quick processing of the luminance frames:

 

This seems to have started as soon as I began imaging M31, as those are all (so far as I can tell) luminance frames. All 125 of them! I can say this from the early look at the M31 stack that if you want a very smooth background, shoot 125 frames! This is a first look at the luminance image, where I've somewhat de-emphasized field stars using PixInsight's Morphological Transformation:

 

 

Incidentally, these are all imaged using the Takahashi CR 0.73X focal reducer on my FSQ-106, so I was operating at  f/3.65 and an effective focal length of about 387mm.

 

Another mystery was easier to solve. I noticed that autofocusing was having a very difficult time. This was traced to a loosening of the connection between the motor and focuser shaft. I've tightened that up now, and just in case that was happening because of overly tight parking of the focuser I'm going to change the focuser's home position.

 

This weekend I hope to actually collect the M31 chrominance, and maybe deeper into September get the California Nebula color data.

 

-------------

 

I'm returning to something I started back in 2020: spectrographic imaging. More about that next time (I hope!)

 

The delight of BackyardEOS, A rare night in February

Last Friday night was an exceptional evening in Minnesota.

• The Moon was out of the sky from dusk to almost 1 A.M.
• It was clear
• The dark site observing field was essentially snowless
• It was an incredibly warm evening--by 1 A.M. it had fallen only to around 40F.
• The wind was for the most part very light to calm, so there was no real wind chill factor.

 Best of all my evening was free!

It's difficult to emphasize how rare that evening was. The February 17 average high and low for nearby Cannon Falls is 29 and 10, so it was a good 20 degrees warmer than average. Usually the warmer weather correlates positively with clouds, too.

I originally intended to image the Witch Head nebula because my previous image of it is rather poor; noisy and crossed by an amazing number of geosynchronous satellites. A slow start to the evening made me go with something a little easier--the far brighter M42 area. It turned out better than i expected for 2.1 hours of 5 minute exposures at f/5.6:

I was able to faintly capture some of the dimmer clouds in the outlying areas just to the left of M42. The red patch at the upper right of center edge is an extension of the Horsehead nebula area.

When M42 began to sink I went to comet 45P and got almost an hour and a half of that:

This wasn't deep enough to get even a hint of the fainter, bluer tail. Oh, well...I'll take it!

One of the best things of the night was using BackyardEOS for the first time. It's a joy to use, and despite its power it keeps things easy to use. Next time I'm going to use it to tackle the mystery dithering!

I also got a demonstration of PoleMaster, a hardware/software tandem that makes getting an excellent polar alignment easy, fast, and actually fun (well, compared to drift aligning, anyway). It's definitely on my to-buy list ($300 from OPT). I would really like to take some very long light frames this year in Nebraska, and this would help. Even though PHD2's polar alignment utility is slick and gives good results, I can see how much easier (and probably better) PoleMaster would make getting a good PA.

Another Year, Another M42

I've imaged good old M42 a couple of times in the past with my DSLR and ST80. This is a more ambitious try, using my ST8300 monochrome CCD and AT72ED:

M42 (click for full size)

What's ambitious is that it's my first serious attempt at an LRGB image where I've given some thought about how to properly combine luminance and color data. This could definitely use a longer integration time--it was only about 15 minutes per channel at f/6, made worse by fairly substantial light pollution.

Notice those spikes coming out of the brighter stars? They're from overhead power lines!

The next clear night I'll try taking some shorter exposures so that I can mask in the overexposed center of the nebula.

Coming shortly will be a report on the Orion 50mm mini-guider. I will be using it for autoguiding on scopes of different focal lengths. It cuts about five pounds off my mount's load by replacing my ST80, which weighs about 6.4 pounds when guiding. This is particularly significant because that 6.4 pounds rides piggyback on my telescopes and has a substantial moment arm.