December 3, 2024

Archives for July 19, 2022

M5 – Globular Cluster in Serpens

M5 – Globular Cluster in Serpens

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: 50x60sec, 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, fair transparency

Lensed Sky Quality Meter: 18.4

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Backyard Nikon, Nebulosity, Photoshop

Like many globular clusters M5 is a relic of the early universe with an estimated age of 13 billion years. It is also one of the largest known globular clusters home to as many as 500,000 stars in a region 165 light years across. Its large size has been a major factor in its longevity. Globulars near the galactic plane slowly disperse as they lose stars to the Milky Way. However, M5 is so large that it has been able to hold on to most of its stars. At magnitude 5.7 M5 is an excellent target for small telescopes.

M5 is currently well placed high in the south at dusk. (Photo credit: John Graham, 530-2022)