M15 – Globular Cluster in Pegasus

Telescope: 8” LX80 @ f/6.3, LX90 mount, altaz mode

Camera: Baader modified Canon 600Da, interval timer

Filter: GSO IR Blocking Filter

Guide scope: None

Exposure: 34x10sec, ISO 1600, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/25sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 18.5

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Deep Sky Stacker, Nebulosity, Photoshop

M15, a bright, condensed globular cluster in a relatively lonely stretch of sky in Pegasus. It is one of the oldest known globular clusters with an estimated age of 13.2 billion years and the first globular cluster found to have a planetary nebula (Pease 1), one of only four planetary nebula associated with a globular cluster. M15 is also one of the most condensed globular cluster and at some point in the distant past it experienced a core collapse that may have heralded the formation of a black hole in its nucleus. This is supported by the fact the M15 is an x-ray source.

This is part of a series of images that I will be taking to explore deepsky imaging using fairly basic equipment and techniques.

M2 is currently well placed in the east as the sky darkens.