NGC 2682 also known as Messier 67 is an old cluster and one of the oldest ones in our sky. It was first discovered by Johann Gottfried Koehler in 1779, This is one of the 20 stellar objects he had compiled in a catalog that was published in 1782. It has a lot of stars that are just as like the Sun, the estimate is more than a 100 and it has more than 500 stars in total. Fun fact this cluster is also referred to as the Golden Eye Cluster and most of the stars are the same age and lie at the same distance but we will talk about this later.

I choose to study it for my Astronomy 113 lab and it was pretty nice to learn. For my study of it, I had to use Afterglow and Skynet, tools that allow for imaging of this star cluster and also used Cluster Astromancer to graph H-R diagrams for the stars in the cluster. H-R diagrams show the relation between a stars temperature and its luminosity and it is used to classify the stars. These tools were very interesting and surprisingly easy to pick up thanks to class instructions.

I collected 15 images in Skynet and I used the B, V, R filter in collecting the images and these were stacked in Afterglow and were used in eventually colouring the star cluster. Below are the coloured images I stack to produce my image of M67 and it is interesting how just layering these pictures together can result in beautiful colored image of the stars

B	V	R

 

Messier 67 happens to be one of the most studied open clusters and I got to look at it twice the first go at it imaging was a problem as I was getting a lot of green from when using the proved pictures and when using my own images I was unable to really tighten H-R diagram. If I were to do it again I would definitely focus more on that

For values I got -10.97 as the proper motion RA and -2.92 as the proper motion Declination. I has 3465 solar masses, a solar mass is the mass of the sun. For metallicity I got -0.102, the metallicity refers to the chemical composition. In astronomy, a metal is anything that is not hydrogen and the scale is Logarithmic so a negative number just means a small amount. For reddening i got 0.05 mag and the reddening effect makes stars look redder as the blue light that is meant to be emitted is blocked by interstellar dust.
This cluster is not one of the most visually interesting star clusters however it has it has some interesting qualities. NGC 2682 has blue stragglers, These stars evolve of the main sequence and “straggle behind”. They will look younger and make the cluster appear younger than they are. They are like old people who are acting young which is funny. Referring to the sentence in the opening paragraphs, these stars are not the same age as the stars in cluster

 

NGC 2682(Messier 67)

Classification	Open Cluster
Mass	3465 solar masses
Physical Radius	10.33
RA, Dec	132.85º , 11.82º
Angular Radius	0.271º
Proper Motion RA	-10.97 (mas/yr)
Proper Motion Dec	-2.92 (mas/yr)
Distance	0.67 kpc
Log Age	9.535 log(yrs)
Metallicity	-0.102 solar units
Reddening	0.05(mag)

 

This is the H.R. diagram of the star cluster and we can see the blue stragglers, they are the stars that fall off the line at the middle, the reason they make clusters younger is simply cause of their blue colour. Typically hotter and younger stars emit more blue light i.e. they are burning brighter while cooler stars emit more red light like our sun. These blue stars emit blue light despite being older. Here is an article about blue stragglers.

Also here is my revision of the star cluster on Astronomicon. With the analysis complete, I find that my fascination for the heavens and stars is a bit reignited. I find it interesting how we can measure and observe the properties of the stars that are so far away. This puts to perspective human intelligence and ingenuity. I am happy to be able to partake in this type of study.