November 11, 2024

NGC 869 & 884 – The Double Cluster in Perseus

NGC 869 & 884 – The Double Cluster in Perseus

Telescope: Meade 10” LX850 ACF @ f/8, Orion Atlas EQ-G

Camera: QHY 367c Pro, GSO IR Blocking Filter

Guide scope: Astro-Tech 60mm, ASI120MM Mini, PHD2

Exposure: 76x60sec, gain 2800, offset 50, -10C, saved as Raw16/FITS

Darks: 32x180sec, gain 2800, offset 50, -10C, saved as Raw16/FITS

Flats: 64×0.250sec, tee shirt flats taken at dusk

Average Light Pollution: Red zone, Bortle 8, poor transparency, moonlight

Lensed Sky Quality Meter: 17.9

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: SharpCap Pro, Deep Sky Stacker, Nebulosity, Photoshop

For a long time there was some debate as to whether the two clusters that make up the Double Cluster are actually associated with each other or just happened to appear in the same line of sight with one lying behind the other. It now appears that they are indeed lying next to each other, each about 7,000 light years away and about 100 light years apart. However, there is some evidence that the two clusters are of different ages, so while they may have formed separately from each other, they are now traveling companions.

The Double Cluster is currently rising in the northeast after sunset.