September 23, 2024

M5 – Globular Cluster in Serpens

M5 – Globular Cluster in Serpens

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 28x120sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/80s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze

Lensed Sky Quality Meter: 18.4 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, 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 currently rises in the east during the early evening and is visible for most of the nigth.