January 18, 2025

M62 – Globular Cluster in Ophiuchus

M62 – Globular Cluster in Ophiuchus

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Full Spectrum Modified Nikon D810, Baader Mk III MPCC

Filter: GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ZWO ASI120MM mini, PHD2

Exposure: 43x60sec, ISO 200, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/20sec, Tee shirt flats taken at dusk

Average Light Pollution: Red zone, Bortle 8, poor transparency

Lensed Sky Quality Meter: 18.1

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Backyard Nikon, Nebulosity, Photoshop

M62 is one of several small globular clusters that are well placed for observing during the early evening hours this time of year. M62 appears small in part due to its great distance; 25,000 light years from Earth and 5,500 light years from the galactic core. It is actually one of the larger clusters in the Milky Way with an estimated mass of 1.2 million suns. Visually, M62 appears a bit lop-sided with the core shifted off-center to the east giving it a comet-like appearance. This may be a result of the cluster’s close proximity to the galactic core.

M62 is currently placed low in the south at dusk.