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Capturing Andromeda

I’ve always wanted to take a picture of the Andromeda Galaxy. My first attempt was interrupted by clouds, and I had several issues with the data. Most of the problems were my fault. I did not know how to configure the camera or mount properly, and I used the wrong filter. I ended up with an image that was a bit out of focus, not correctly framed, and with amp glow. The image below is the first picture I took of Andromeda.

I wanted a better picture, so I needed to get at least an hours worth of data. I looked at a couple of weather apps to find a night that would be clear. I use Astropheric on my phone and confirm with The Weather Channel. Once that night came, I set up the telescope outside the same way as I had before but used the Optolong L-Pro filter instead of the Optolong L-Enhance. I also added a Dew-not heater strap on the telescope to keep the moisture away.

Last time I used a Bahtinov mask to focus on a bright star, but I did not use any software to help with the focus. This time I used the focus assistant in SharpCap with the Bahtinov mask. It was straightforward to use the software. It keeps a graph of the focus so you can quickly find the best setting as you make adjustments. A Bahtinov mask is definitely something you should get to help you focus your telescope. Be sure to try the focus assistant if you use SharpCap.

Bahtinov Mask

The other issue I was having on my previous session was the GoTo functionality with my mount. I traced that down to a bad polar alignment. This time I took my time with the Polemaster software to make sure I followed all the steps correctly, and I used the polar alignment feature in SharpCap to validate. Once I verified the polar alignment, I connected the telescope to my computer using CPWI and did a two-star alignment using Deneb and Vega. I was pleasantly surprised when both stars showed up almost precisely centered after the GoTo commands. Now it was time to point towards Andromeda.

With the telescope centered an Andromeda, I started to configure all the software I needed to make sure I captured at least an hour of data. I used SharpCap to control the camera and set it to take 30 2-minute exposures. I started PHD2 to help with guiding. I went back inside and left the rig alone to do its work.

Once the hour passed, I went to check on the results and was happy to find that was able to capture all 30 shots. I noticed two issues; PHD2 was not guiding properly. The graph looked like a sine wave, and after a bit of debugging, I realized that PHD2 could not move the mount at all! I think its a problem with CPWI, other tools can control the mount with no issue. The other problem was with the dew heater strap. It never turned on. I’ll have to figure these out before my next session.

I used Astro Pixel Processor to process all the Andromeda data and ended up with this:

The Andromeda Galaxy

The final image came out better than I expected, a huge improvement over my first attempt. The galaxy is centered, there is much more detail, and better focus.

The CGEM II mount has been doing an excellent job tracking on its own. I can’t wait to see how much it will improve after I get PHD2 working. I still had the amp glow problem because I did not take any dark frames. I was able to get rid of most of it using Astro Pixel Processor. I’ll create a tutorial on how I process the images soon.

The night was still young, so I decided to capture one more galaxy, the Pinwheel Galaxy. I only took five two-minute exposure shots because I wanted to spend more time processing the Andromeda data. I did not try PHD2 again since that problem is going to take time to debug.

Again using Astro Pixel Processor, here is the Pinwheel Galaxy:

The Pinwheel Galaxy

Ten minutes of data is not enough for this galaxy. You can barely make out the spiral arms in the center. I will re-visit this galaxy soon.

Bonus image of the moon that I captured before calling it a night.

My next session is going to focus on a nebula. I need to fix the issue with PHD2 and the dew heater strap. I noticed in the Andromeda data that there was a drop of water in the corner, so moisture is definitely a problem. I am also going to try to use dark frames to see how they improve the images and try to use PixInsight to process the data.

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  1. Pingback: First Time Capturing a Nebula | Ruben's Thoughts

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