Hello everyone, I hope all is well. It has been some time since I have shared anything on my blog.
At the time I wrote this post, in Missouri, it was late in the summer season of 2022; Labor day weekend, and I have been contemplating the idea of spending more time observing objects in the night sky, a fancy of mine during my adolescent years.
You see my Mum has been one of the biggest inspirations and supporters of my passions, forever. So, on my birthday she asked what l would like as a present. I grinned and told her a telescope! I vividly remember, on Christmas day, 1986, I had a 45X to 450X kid’s telescope waiting for me under the tree. I have very fond memories of that scope, Thanks, Mum.
What is Astrophotography? – According to Wikipedia: Astrophotography, also known as astronomical imaging, is the photography or imaging of astronomical objects, celestial events, or areas of the night sky.
The night sky is an inexhaustible source of inspiration for aspiring and established Astrophotographers and Astronomers. Whether you want to capture images of the Moon, try your hand at shooting the Milky Way or plot the stars on a star chart.
How can you achieve stunning images? This is where the journey picks up.
Getting back to the summer of 2022, it has been quite some time since I looked through a scope, and not wanting to go down the proverbial rabbit’s hole, I asked Bill for a few pointers – in 2020, he captured a beautiful image of the Andromeda Galaxy also known as Messier 31, M31 or NGC 224 and accompanied with a fantastic detailed blog: https://ozarkbill.com/2020/08/22/m31-the-andromeda-galaxy/ – I must have read that 1925-word blog at least 10 times. From Bill’s blog, I took the recommendation and visited Cloudy Nights Forum at www.cloudynights.com, a very useful resource for those that are wet behind the ears or for the veteran astrophotographer. Also, you have to check out YouTube, there is a substantial amount of usable content.
With all of this information, I decided to make the initial investment in a GoTo Mount, initially, I was going to use my mirrorless camera, but after a trial night, I could not achieve Polar alignment. I opted for a dedicated one-shot color-cooled camera.
This will be my first few nights with the gear, I had zero success with my attempts to gather light. Due to a myriad of errors: unable to achieve polar alignment, unable to plate solve, unable to gain focus and sheer inexperience. These errors in the field made me realise that I would benefit from having a completely automated workflow. I invested in a smart WiFi device controller and an EAF (electronic assist focuser) I knew the learning curve would be steep, I also utilized Facebook groups for assistance, I cannot thank Alejandro M, a fellow astrophotographer from Costa Rica. He stepped me through the polar alignment process and I was not only able to achieve polar alignment, but I was also able to successfully plate solve – plate solving is a technique that measures precisely where the telescope is pointing by taking an image and then comparing the star field in a database of stars.
During the time, when I was not photographing the sky, I worked on cable management for the rig, working in the IT field, I am not fond of the rat’s nest of wire look. I got all of my wires bundled and routed all power to a central base and with Missouri’s notorious RH (relative humidity) I picked up two dew heaters, to use on nights when dew could be problematic on the front end lens element. Well, I am ready for the first light, here is how things transpired on the night before the new moon.
About the Target:
Target subject: Andromeda Galaxy and her companion galaxies – with a magnitude of 3.44, RA 88h 43m 59.8s and Declination +41° 23’ 42.9”. The earliest recorded observation of the Andromeda Galaxy was in 905AD by the Persian astronomer Abd Al-Rahman Al Sufi, who described it as a “small cloud, a barred spiral galaxy, later classified as a Messier 31 object in 1771 after French astronomer Charles Messier.
The Andromeda Galaxy, also referred to as NGC 224 is approximately 2.5 million light-years from Earth and the nearest large galaxy to the Milky Way. The galaxy’s name stems from the area of the Earth’s sky in which it appears, the constellation of Andromeda, which itself is named after the princess who was the wife of Perseus in Greek Mythology. It is bright enough to be seen by the naked eye on a moonless night. Compared to the Milky Way which has 200-400 billion stars, reports claim there are 1 trillion stars in the M31 galaxy. It also has the distinction of being the largest galaxy of what is called the Local Group – a collection of more than 54 galaxies including the Milky Way, the Triangulum galaxy and many other satellite galaxies.
I bounced the idea of imaging M31 to Bill, over the weekend of October’s new moon, and he was available. We drove an hour west; away from the city to a location which is less light polluted that the metro St. Louis area. We arrived at the site two hours before nautical twilight which was 637pm. Astronomical twilight is at 745pm CST. At this time of the year, look towards the Northeast sky at 38° above the horizon and you will see the glow of the Andromeda galaxy.
Arriving early gives time to go through the initial set-up process and wait for the darkness to approach. The forecast called for clouds, which was spot on 70% or so of the sky was covered. The wind gusts were between 14-17 mph, which was concerning at first, but later on, it helped disperse the clouds by 930pm.
Stargazing is at its best on a crisp, clear night when the moon is in the crescent or gibbous phase. “First Light” – a term coined for the first use of the telescope. Location: Danville Conservation Area, New Florence, MO – Bortle class rating of 4, the sky here is much darker than where I live, which for reference has a Bortle class rating of 8.
Imaging gear list:
Mount: Skywatcher Star Adventurer, Control: Control Module: ZWO ASIAIR, Main Scope William Optics RedCat 51, Camera: ZWO ASI533MC, Focuser: ZWO ASI EAF, Filter: Optolong L-Ultimate, Powerbox and Dew Heaters.
Polar alignment Process:
Before I can start imaging, I need to get a successful polar alignment with the North Celestial Pole. My PA workflow: set one of the tripod legs to face NCP, attach the SWSA GTi mount on the tripod, attach the main scope, guide scope, imaging camera, and the cables needed to connect the scope to the imaging system: ASIAIR.
Next, I balanced the scope for the RA (right ascension) and Dec (declination) which are the coordinates in the sky that correspond to the longitude and latitude on Earth. RA measures east and west on the celestial sphere and is like longitude on the Earth. Dec measures north and south on the celestial sphere and is like latitude on the Earth. This took about 5-8 minutes. I automated focus on the stars, using the EAF, which took roughly 5-8 minutes and lastly I did a plate solve – Plate solving is a method used to determine exactly where the telescope is pointing in the sky by comparing the star field in an image to a database of stars and that took roughly 4-7 minutes. I was able to locate my target M31 which appeared as a faintly glowing orb on my imaging tablet. You cannot imagine the relief, my workflow actually works. Big thanks to Alejandro and Bill. The night was shaping up very nicely!
Imaging Capture Workflow:
Using the ASIAIR, I automated my imaging frame sequence, using the AutoRun – Lights, Darks, Flats and Bias. The ASIAIR will take an image of M31 every 60 seconds.
Things were humming along until I noticed a message on the imaging tablet, “Meridian Flip” in one hour and fifteen minutes – The meridian flip is the point where my target object crosses the meridian from the east to the west. I was not prepared for this and as a result, I lost about 45 minutes of imaging time – due to having to rotate the scope, I essentially had to repeat polar alignment, balance the RA/Dec, reacquire focus, plate solve and relocate M31. One of the many lessons I learned this night and another thing, please remove your filter before you go imaging.
The second lesson for the night, while I was pleased with “first light” I captured data from 945pm until 315pm with my L-Ultimate filter (which boosts the Hydrogen Alpha and Oxygen signals) attached to the imaging rig. What a rookie move! When imaging galaxies,” Kids, leave the filter in your bag, imaging galaxies in RGB will more than certainly suffice.” When I removed the filter; not only was there more data, I saw the galaxy in an even more dynamic range. I did manage to collect 15 lights or subs of the unfiltered M31. I hope that stacking it with the other 177 lights will result in something show-worthy for my night’s efforts.
The amount of data collected on M31 was: 188 lights, 40 Darks, and 30 Flats. My total time collecting exposures was 3.13 hours on Lights, 0.66 hours on Darks and 0.5 hours on Flats. All of these images are in their own individual folder and awaiting processing. Now the fun begins – I really do enjoy a challenge, I have an ok grasp of Adobe Photoshop and Lightroom, and I really wanted to streamline my image processing, so I opted for PixInsight. A journey into learning PixInsight!
Who does not love a challenge, I opted not to do my main image post-processing in Photoshop or Lightroom, rather I emailed the team at Pleiades Astrophoto. I figure starting off with the Trial licensed software, would be best. I also downloaded a few other recommended plug-ins for PixInsight.
After I received email confirmation that my trial licensed software was validated, I wasted no time and added all of the recommended plug-ins. With my Lights, Darks and Flats all segregated in their folders. I started the weighted pre-processing (WBPPS) in PixInsight. Implementing some highly recommended suggestions for Image integration and image registration. I was ready to click run on my calibrations frames: 188 lights, 40 Darks, and 30 Flats. The entire process in PixInsight took 21 minutes and 38 seconds. My faults in this imaging session: I need to master Meridian Flip, and increase the number of flats, darks and bias frames.
The final amount of usable images was 173 frames, with 2h and 53 min of total integration time. Not bad for “First Light” and a few critical learning opportunities. Which is why I will revisit it in the future. There is much more to be learned and my process needs refinement.
I must admit, the younger version of myself preferred a certain degree of perfection when it involved projects I embarked on. What I have learned over the past 10 years, perfection can be a hindrance and while it’s ok to strive for perfection, mistakes are essential learning opportunities.