Had a few hours of clear skies last night, and captured a globular cluster I hadn’t imaged before: M92. It’s a pretty one, and I’m surprised it’s not more popular. It’s in the constellation Hercules, and I suspect it just gets overshadowed by its even more spectacular neighbor, M13.
Globular clusters were enshrouded in mystery for a long time; nobody was really sure how they formed, why they are so old, or why they appear outside the plane of our galaxy. The latest research seems like common sense in hindsight; globular clusters are just stars that formed out of the gas that clumped together to originally form our galaxy. Within the plane of the galaxy, globular clusters were torn apart by all the gas within the galactic plane to scatter them. In this theory, there’s really no difference between the globular clusters surrounding our galaxy and the open clusters within it – it’s just that the globulars formed in an area where they were allowed to remain intact.
M92 is 26,700 light-years from earth and spans about 100 light-years across. It’s thought to contain about 330,000 stars, which are 14.2 BILLION years old.