The Pleiades: A Naked Eye Star Cluster

The Pleiades

The Pleiades(M45), which are also called the Seven Sisters, is an open star cluster in the constellation of Taurus. It is one of the brightest star clusters in the night sky and can be easily seen with the naked eye. For this reason, there are myths and stories about the Pleiades from all around the world.

In Greek Mythology, the Pleiades were considered to be the 7 daughters of Atlas. In a legend of the Kiowa Tribe of the Plains, the Pleiades were 7 girls that were saved from a bear by a Great Spirit and put in the sky. It was known as the seed scatterer by the Inca, Mao by the Chinese, and is known as Subaru in Japan(which is where the name and logo of the car company come from). In India, the Pleiades is known as Krithika and represents the 6 wives of 6 rishis(sages).

In my opinion, the Pleiades are the prettiest star cluster you can see without a telescope. It is also one of the easiest to photograph, which is why I have tried photographing them multiple times.

The first time I tried taking pictures of the Pleiades was in February 2020, when I was new to astrophotography. I didn’t really care about how it came out and I only took about 150 shots before stopping for the night. In the end, it didn’t come out that well and I decided I would try again later. Later ended up being December 2020.

My first try photographing the Pleiades

In early December 2020, I wanted to try and photograph the Pleiades again, and this time be able to see the nebulosity around the stars. For that purpose, I took 630 light frames and 40 dark frames for stacking, which is more than I have ever taken before. If you don’t know what stacking is, it is basically just using software to align the stars in all the pictures I take(in this case 630), and finding the average of each pixel. What this does is reduce the amount of camera noise(which is caused by the electronics within the camera), and brings out details that may not be seen in a single image.

I was quite excited about how it would come out since 630 is more double the shots I had ever taken before. I stacked the images the next day using DSS and I tried to edit them. It first seemed like the image would come out really well, but soon I realized that whenever I tried to filter out the background light pollution, most of the detail on the nebulae got filtered out too. No matter how hard I tried, there was no way I was going to get rid of the background light pollution without losing detail, the nebula was just too faint. I ended up with a final image that was much better than what I had before, but it fell short of my expectations. I sat on the image for a full month, before trying again. It came out slightly better this time, but I still lost a lot of detail. I finally decided that I was going to try to take photos again.

My attempt in December. The nebula is very faint and there is a lot of noise

Just last weekend, I tried again. This time instead of taking pictures from my light-polluted backyard, we decided to go and try taking pictures from a darker location, so we went to the nearby Lake Jordan. I wanted to take 600 pictures just like last time, but things did not go as planned. For the first 300 shots, things went well, but after that things went downhill. My tripod started acting up, and whenever I tried to get the Pleiades in the frame it would just move. To make matters worse the Pleiades were near the zenith(right above us), making it even harder to aim my camera. I eventually found them, but whenever I took pictures it came out blurry, and I couldn’t figure out why. I tried to focus and refocus on another brighter star, but that wouldn’t work either. Soon the stars completely stopped showing up in the picture, and I was confused and frustrated. That’s when I decided to check the front lens of the camera to see if anything was wrong, and that’s when I saw that it was completely fogged up which is why nothing showed up in the pictures. It was getting cold, and I knew that we had to leave, so took the dark shots and I got in the car. I was disappointed that I couldn’t get the full 600 shots even though the 300 would be quite adequate. I have never taken good pictures from a dark area before so I didn’t know what to expect. The next day I stacked the images and edited them in GIMP.

My final image of the Pleiades. You can clearly see the nebulosity.

Even before I was done editing, I knew things were better. Whenever I took pics from my light-polluted backyard, they had a lot of vignetting and ended up quite noisy, but this time there was very little vignetting, and less noise. It was also much easier to bring out the detail while filtering the light pollution since there was much less of it. In the end, the image came out much better than the previous one, and looks somewhat pretty. I feel like I have a lot of room for improvement, but I also am pretty happy with how I did. Though astrophotography can be really hard and frustrating sometimes, in the end, it pays off. I hope that all of you take the opportunity to see the Pleiades for yourselves, it will be truly worth your time.