February 2, 2025

Archives for December 17, 2020

Eris – Trans-Neptunian Object

Eris – Trans-Neptunian Object – 11/8 & 9/2020 22h30m EST – Animated GIF
Still Frame showing the location of Eris

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

Camera: ZWO ASI071MC Pro, -10C, Gain 200, Baader Mk III MPCC

Filter: Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, Meade DSI Pro II, PHD

Exposure: 7x240s (11/8) & 11x240s (11/9), saved as FITS

Darks: 32x240s, saved as FITS

Flats: 32×0.2s, sky flats taken at dusk

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

Lensed Sky Quality Meter: 18.5 mag/arc-sec^2

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

I have wanted to try this for a long time and I have been waiting for a pair of nights with perfect transparency to give it a try. However, my window of opportunity is closing for this year so I decided to go ahead and give it a try, and much to my surprise… success! This is a composite of two images taken 24 sours apart at about 10:30pm EST on the evenings of Novermber 8th and 9th in Cetus. The tiny smudges near the center of this field are the dwarf planet Eris, one of the most distant objects in the solar system. Eris is currently 8.8 billion miles from the Sun, almost 3 times farther than Pluto. It takes sunlight over 13 hours to reach Eris, and another 13 hours for the feeble reflected sunlight to make the trip back to Earth. Eris is about the same size as Pluto and with a more reflective surface it is so cold out there that the surface is likely coated with frozen methane, but unlike Pluto the sunlight is so faint that it is unlikely that the surface has been darkened by the formation of tholins. Shining at an incredibly faint Mv 18.8 this is the faintest object that I have been able to photograph and identify from my backyard

NGC 2371/2 – Planetary Nebula in Gemini

NGC 2371/2 – Planetary Nebula in Gemini

Telescope: Meade 12” LX850 ACF @ f/8, Orion Atlas EQ-G

Camera: ZWO ASI071 MC Pro, -10C, Gain 200

Filter: Orion Imaging Skyglow Filter

Guide scope: Astro-Tech 60mm, ASI290MM Mini, PHD2

Exposure: 22x240sec, saved as FITS

Darks: 32x240s, saved as FITS

Flats: 32x1sec, Tee shirt flats taken at dawn

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

Lensed Sky Quality Meter: 18.6 mag/arc-sec^2

Stacking: Mean with a 2-sigma clip.

White Balance: Nebulosity Automatic

Software: Nebulosity, Deep Sky Stacker, Photoshop

NGC 2371/2 is a fascinating little planetary nebula in northern Gemini placed midway between Castor and Pollux. When this nebula was discovered it was thought that it was actually two separate objects, hence the two New General Catalog (NGC) numbers. The core nebula shows two clearly resolved lobes with two faint outer arcs. The seeing was pretty rough when this image set was taken so I down-sampled it a bit to keep it from looking too soft. I’ll be taking another look at this nebula on an evening with better seeing.