Open Clusters M35 and NGC 2158 are seen here in the constellation of Gemini.

M35 is a spectacular large open cluster located 2,800 light-years from us. In this image it takes up most of the top left of the frame. Shining at magnitude 5 and with an apparent size of 25 arcminutes, it is visible to the unaided eye as a diffuse object off the foot of Gemini from a dark-sky observing site. M35 is a relatively young cluster estimated to be 150 million years old. It was discovered in 1745 by Philippe Loys de Chéseaux.

It is accompanied by a golden jewel-like smaller companion, open cluster NGC 2158, located 15 arcminutes to the southwest of M35. It is seen at the lower right of the photo. NGC 2158 contains more stars and is more compact than M35. It shines at magnitude 8.6 and is 5 arcminutes in angular diameter. It is located 11,000 light-years away, which is why it seems so much smaller. It is estimated to be 1 to 1.5 billion years old. At this age, most of the hot blue stars are gone, leaving only older yellow stars. NGC 2158 was discovered by William Herschel in 1784.

North is to the top in the above image.

Messier 35, NGC 2158 Catalogs: M35, NGC 2168, OCL 466 NGC 2158, OCL 468 Object Type: Open Clusters Magnitude: M35: 5.1v NGC 2158: 8.6v Size: M35: 25' NGC 2158: 5' Constellation: Gemini Image Field Centered At: RA: 06h 08m 34s Dec: +24° 16' 38"