November 21, 2024

M13 – Globular Cluster in Hercules

M13 – Globular Cluster in Hercules

Telescope: Light Switch 8 @ f/6.2 (Optec 0.62x focal reducer), altaz mode

Camera: Full Spectrum Modified Canon 600D, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 31x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/10sec, 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: Deep Sky Stacker, Nebulosity, Photoshop

Globular clusters are relics of the ancient universe and M13 is no exception with an estimated age of 12 billion years. Their great age is an indication of their unusual stability. One consequence of this stability is that any heavy elements that their stars have made remains buried in their cores and the cluster itself has little, if any, interstellar dust. M13 is one of the few globular clusters with a dust-like feature that can be seen as a dark lane extending to the upper left of the core. It is possible that this dust lane is an independent object that just happens to be in front of the cluster.

M13 is currently in the northwest at sunset.