Messier 3 Global Cluster

May 2021

Imaging: TS80 apo, Canon 1000D 400ISO, Baader neodymium
Subs: 183x60 (3h), bias, darks, and flats
Processing: PixInsight

(Additional notes below)




After 2 months in Germany for repair, my new scope is back! The TS Optics Photoline 80 is an apochromatic. In contrast to my ST120 achromatic, it focuses red, green, blue simultaneously which should produce pinpoint stars versus the horribly bloated blue messes from my earlier images. This is my first image with the scope, and I captured this over a single night in late May 2021.

Messier 3 is a globular cluster comprised of over 500,000 stars tightly packed. It is one of the oldest and brightest, estimated to be about 11 billion years old. The center is about 32000 ly from us. At this time of the year, it passes almost directly overhead (slightly south) over the night, but it is too faint to see naked eye in typical skies. This was apparently the first object identified by Messier himself (begs the question as to why this isn't named Messier 1) though he wouldn't have been able to tell these were individual stars (versus a nebula). Looking up at the sky, we might think that the stars are white. But they have a variety of colors (depending on their temperature) as you can see in this image.