M57 – The Ring Nebula in Lyra

Telescope: Unitron 155 4” f/15 refractor, Atlas EQ-G

Camera: Canon EOS Ra full frame DSLR

Filter: 2” GSO IR Cut Filter

Guide scope: Orion 50mm Guidescope, ASI120MM, PHD, Dithered every 4 subs

Exposure: 27x120sec, ISO 800, saved as RAW

Darks: Internal (Long Exposure Noise Reduction)

Flats: 32×1/80s tee shirt flats taken at dusk

Average Light Pollution: Bortle 8, poor transparency, haze

Lensed Sky Quality Meter: 18.3 mag/arc-sec^2

Stacking: Mean with a 1-sigma clip

White Balance: Nebulosity Automatic

Software: Backyard EOS, Deepsky Stacker, Nebulosity, Photoshop

Visually, the Ring appears as a ghostly smoke ring about the size of Jupiter. The nebula itself is not actually a ring, but more likely a torus or a short hour-glass, we just happen to the looking down the long axis, giving the nebula its characteristic shape.

M57 currently rises in the northeast a few hours after sunset.