M35 - Open Cluster in Gemini

HD 41996mag 7.42G0HD 42086mag 7.55A3VHD 41940mag 8.14B8HD 252260mag 8.57K5HD 42066mag 8.73A2HD 252405mag 8.78HD 252353mag 9.10AHD 251671mag 9.26B8HD 252373mag 9.29B7IIIHD 252504mag 9.32B9.5VHD 252199mag 9.38A0VTYC 1864-951-1mag 9.39HD 252319mag 9.40G5HD 251944mag 9.46A0mHD 252404mag 9.67AHD 252480mag 9.69A0VTYC 1864-545-1mag 9.69TYC 1864-677-1mag 9.70TYC 1864-607-1mag 9.76HD 252318mag 9.80AHD 252176mag 9.80A0VHD 252153mag 9.82A0HD 252201mag 9.87AHD 252202mag 9.90A0HD 252048mag 9.94B8III-IVSi

0 — normal image

M35, paired with the open cluster NGC 2158, in LRGB.

Location: Eldorado Star Party, 2005, near Eldorado, Texas

Date: November 4, 2005

Seeing: 2/10

Transparency: 8/10

Temperature: 50 degrees F (-20c on camera)

Scope/Mount: 12.5" RCOS RC with Paramount ME

Camera: SBIG STL-11000M astro CCD camera

Exposure Info: LRGB image; 100:40:30:40 RGB (20 minute subexposures L, 10 minute subs RGB, color binned)

Processing Information: Acquisition in CCDSoft. Calibration, Registration, DDP, and RGB channel combine in MaxIm DL 4. LRGB combine, color balance, levels/curves, sharpening, and noise removal (Noel Carboni's Astronomy Tools) in Photoshop CS.

Exposure Notes: Exceptionally poor seeing and wind during the blue channel exposure.

About this Object

At the foot of the twins in Gemini is a large open cluster known as M35. The cluster shines at mag 5.1 and consists prominently of young, hot blue stars. There is some reflection nebulosity to this cluster, but it's very difficult to capture. This photography merely hints at it. The larger, looser grouping of stars in the upper left hand corner is M35.

Paired with M35 in this photo is the tight open cluster NGC 2158. This cluster of older stars shines at a magnitude of 8.6.

M35 is easily seen with binocular in just about any sky. Its companion is a little more difficult to see, though even small scopes can bring it in if the sky is dark enough.

🤖 AI-drafted · unverified

What it is: M35 is a rich open star cluster containing several hundred stars — about the width of the full Moon and visible to the naked eye under dark skies.
Constellation: Gemini
Distance: ~2,800 light-years
Apparent magnitude: 5.1
Angular size: ~28 arcminutes
Coordinates: RA 06h 09m, Dec +24° 21′

This summary was generated by an AI assistant from general astronomical references, not from Jay's own notes on this specific image. Treat every detail above as a starting point for research, not settled fact.