Andromeda galaxy is our closest neighbor. One might say we might even be roommates in 4.5 billion years. This is one of the most popular targets for astrophotography due to its huge size (about 5° across the sky) and relatively bright nature. Under good clear seeing conditions, Andromeda can be seen with the naked eye and can be seen very clearly using binoculars. At 2.93 million light-years away, this is the furthest object our eyes can see. Even with a small 6-inch dob, one can see the dust lanes, which is sure to bring a smile.
In the early days of astronomy, Andromeda Galaxy was known as the Great Nebula, as the idea of galaxies were not present at the time. There were great debates that Edwin Hubble eventually settled in 1925 using science that I do not understand.
Along with M31 are the dwarf elliptical galaxies M32 and M110. M31 is part of our local group of galaxies, including our own Milky Way, the Magellanic Clouds, and the Triangulum Galaxy.
M31 is on track to collide with our own Milky Way Galaxy and merge int a gigantic elliptical galaxy in about 3 billion years.
My first attempt at M31 was a total failure, I did not know how tracking worked, and I had clear visible star trails. This was the first time I hooked up a camera to a telescope. I did not know about auto guiders and acquisition software. I had so much more to learn, and I was set on trying this again. Check out my following attempts in the tabs below.
Here you can see what happens when you try to take long exposures unguided with bad polar alignment.
Here you can see the area of the sky in Andromeda imaged.
This is my third try with Andromeda, the first two can be seen in the other tab and above in the general description. I had high hopes for myself since I’ve only gotten better since my last attempts with astrophotography.
I attended Black Forest Star Party and was blessed with about 15 hours of somewhat clear skies. Out of that, I got about a little over 10 hours of usable data. This was my first galaxy captured with a mono camera. The detail and quality of data are a whole lot better than a DSLR or an OSC camera.
The following steps were performed with the Ha, Lum, Red, Blue & Green stacked data:
- Dynamic Crop
- Linear Fit
- Dynamic Backgroud Extraction
The following steps were performed to the Luminance data:
- EZ Denoise
- Histogram Transformation (I intentionally clipped some of the data)
Once I had the gradients smoothed out, I started working on the Ha data to integrate that into my images. I found a very helpful tutorial on a YouTube channel, Entering into Space. I found this a very helpful tool to get me started on isolating Ha and then adding it into the Red channel. Here are the steps I took to isolate and then add the Ha.
- I created a new image by applying this formula to the Ha channel:
- “Ha” refers to the ImageIdentifier of the Ha Channel image.
- “R” refers to the ImageIdentifier of the Red Channel image.
- 80 is (I think) the intensity to which to extract the data.
- 5 refers to the bandpass nm of my Ha filter. In my case, I have a Chroma 36mm Ha 5nm filter.
- I then renamed the new image as new_Ha
- I then went to the Red channel image and applied the following formula:
- “$T” refers to the target image. In this case, is the Red image.
- “new_Ha” refers to the image created in the previous step.
- 5, in this case, is the boosting number. This can be higher, depending on how much intensity you want to add into the R channel.
- In this step, I had PixelMath replace the image.
I then combined the Red, Green & Blue images using LRGB Combination. I did not use the Luminance data in this step. I then performed the following steps in PixInsight:
- Background Neutralization
- Photometric Color Calibration
- EZ Denoise
- Histogram Transformation
- Extract CIE L* Compoment from RGB image.
- LRGB Combination (CIE L* Component in L x 3)
- Curves Transformation (Using a color mask from the R data)
- SCNR (Removed Green)
- Curves Transformation (x2 with range masks and then x2 with the same mask inverted)
- LRGB Combination (Using the Lum data)
- HDR Multiscale Transformation
- LRGB Combination (CIE L* Component in L x 2)
- Star Mask
- Morphological Transformation
- Dark Structure Enhance
- ICC Profile Transformation
This was annoyingly hard for me to process because of how large the target was and how many different components there are to this image. The dynamic range of the target did not help either. Regardless, this was a lot of fun for me to acquire and process. I hope to add more data to this over the next couple of years and see how much more detail I can extract out of this target.
- Telescope: Explore Scientific FCD100 Series 127mm f/7.5 Carbon Fiber Triplet ED APO Refractor Telescope
- Camera: ZWO ASI2600MM Pro, 100 Gain, -10°C
- Guiding: ZWO Off-Axis Guider with Helical Focuser
- Guide Camera: ZWO ASI290MM Mini.
- Mount: iOptron CEM60
- Software: SGP for image acquisition. PixInsight is used for stacking and editing. Imported to Photoshop for final touchup and watermarking.
- Other Accessories: Dew-Not Dew Heater, Starizona 0.65x Apex-L Focal Reducer/Flattener, MoonLite NiteCrawler Rotating Focuser, PrimaLuceLab Eagle 4S, ZWO EFW 36mm 7 Position
- Exposure Time: 10 hours 6 minutes
- Date: September 30 & October 01, 2021
- Location: Cherry Springs State Park, PA
- Bortle Dark-Sky Scale: 2
- Mean SQM: 21.4
- RA center: 00h 42′ 58″
- DEC center: +41° 16′ 32″
- Orientation: 95.345 degrees
- Field radius: 1.247 degrees
- Magnitude: 3.4
- Resolution: 3720 x 2476
This was my second attempt with Andromeda. My first attempt is highlighted above with all the star trails. This isn’t much better, I was not paying attention to focusing, and is completely out of focus. I was still proud of this image as I had an amazing time capturing this target and helped learn about polar alignment and many other basics of imaging. I did get enough exposure to see the dust lanes.
Next time the conditions are ideal, I want to focus again on getting better data.
I did not edit this image. I had a very kind Redditor help me get this image to life.
- Telescope: Orion ShortTube 80mm f/5
- Camera: Canon T4i
- Mount: Orion Atlas EQ-G
- Software: Pixinsight
- Other Accessories: AstroZap Dew Heater
- Exposure Time: 30 minutes (30 X 60 seconds)
- Exposure Start: 01:44 AM
- Date: June 29, 2014
- Location: Cherry Springs, Pennsylvania, United States
- GPS Coordinates: Lat. 41.66384, Long. -77.82321
- Temperature: 66°F/19°C
- Bortle Dark-Sky Scale: 2.00
- Avg. Moon age: 1.97 days
- Avg. Moon phase: 4.34%
- RA center: 0h 41′ 15″
- DEC center: +41° 14′ 52″
- Orientation: 237.176 degrees
- Field radius: 1.907 degrees
- Magnitude: 3.4
- Resolution: 3124x 2085