November 23, 2024

Stephenson-1 – Open Cluster in Lyra

Stephenson-1 – Open Cluster in Lyra

Telescope: ES Comet Hunter MN6 at f/4.8, Orion Atlas EQ-G

Camera: Baader modified Nikon 610

Filter: 2” Orion Imaging Skyglow Filter

Guide scope: Williams Optics 50mm, ASI290MM mini, PHD

Exposure: 16x60sec, ISO 400, 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, poor transparency

Lensed Sky Quality Meter: Too many clouds to get a good reading

Stacking: Mean with a 1-sigma clip.

White Balance: Nebulosity Automatic

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

This field is centered on Stephenson-1, and open cluster in Lyra near the beautiful yellow star Delta(2) Lyra, located just to the southeast of the brilliant Vega. Delta(2) was born a mere 75 million years ago as a fiercely hot blue star, but it burned through its original hydrogen quickly and is now a swollen red giant with a dead helium core. This star enormous, with a diameter of 242 million miles, 1.3 times the diameter of the Earth’s orbit! It’s beautiful red color is clearly visible through a small telescope and shows well in this image. To the upper right of Delta(2) is the wonderfully blue Delta(1). These two stars share the field with a sparse, triangular shaped open cluster of moderately bright stars called Stephenson-1. This cluster is easy to spot with binoculars and places the Delta(2) and Delta(1) stars in a wonderful field when viewed through a small telescope.

Stephenson-1 is currently well placed rising in the northeast early in the evening.