November 23, 2024

M13 – Globular Cluster in Hercules

M13 – Globular Cluster in Hercules

Telescope: Stock Unitron 155c 4” f/15 refractor

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: None

Exposure: 28 (of 32)x15sec, ISO 6400, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/20s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze, low altitude

Lensed Sky Quality Meter: 18.3 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

This is M13, the Great Cluster in Hercules. If you look carefully you can glimpse the tiny galaxy NGC 6207 (Mv 11.6) in the upper left corner as well as a dust lane to the lower left of the cluster. The dust lane is a very unusual feature for globular clusters and it is not clear if this is actually associated with M13 or simply lies in the line of sight with the cluster.

M13 currently rises in the northeast during the early evening.