November 21, 2024

NGC 7789 – Open Cluster in Cassiopeia

NGC 7789 – Open Cluster in Cassiopeia

Telescope: Astro-Tech 8” f/8 Ritchey-Chretien, Orion Atlas EQ-G

Camera: Canon EOS Ra, Baader Mk III MPCC

Filter: Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, Starlight Xpress Super Star, PHD2

Exposure: 89x60sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction On)

Flats: 32×1/20sec, Tee shirt flats taken at dusk

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

Lensed Sky Quality Meter: 17.7

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deep Sky Stacker, Nebulosity, Photoshop

NGC7789 is a large and wonderfully rich open cluster located just west of Cassiopeia. It was discovered by Caroline Herschel in 1782 and is sometimes called Caroline’s Rose. It is a delicate object in small to moderate scopes, but blossoms into a rich field in large telescopes. When viewing this cluster I like to spend some time with the field. At first all I will see are the foreground stars and perhaps a soft glow in the background. As my eye adjusts, the first faint stars appear, and then it slowly blooms into a beautiful patch of stardust.

Caroline’s Rose is currently low in the northeast at sunset and is high overhead after midnight.