M35 - NGC 2168

Messier 35 (NGC 2168) is a large, rich open cluster in the constellation Gemini, located approximately 2,800 light-years from Earth. It contains several hundred stars within a diameter of about 28 light-years and shines at an apparent magnitude of 5.3, making it visible to the naked eye under dark skies as a hazy spot near the feet of the Gemini twins. The cluster is estimated to be about 150 million years old and contains a mix of hot blue-white stars and a few yellow and orange giants, providing attractive color contrasts when viewed through a telescope. M35 was discovered by Philippe Loys de Cheseaux around 1745 and independently noted by John Bevis before being cataloged by Messier in 1764. One of M35's most rewarding features for observers is the presence of NGC 2158, a much smaller, fainter, and more distant open cluster located just 15 arcminutes to the southwest. NGC 2158 lies about 11,000 light-years away and is roughly 2 billion years old, making it appear as a dense, unresolved smudge in amateur telescopes. The contrast between the two clusters, one young, bright, and nearby, the other old, faint, and distant, provides a wonderful lesson in the diversity and perspective of deep sky objects. M35 spans about 28 arcminutes, nearly the size of the full Moon, and is best appreciated at low magnification in binoculars or a wide-field telescope. Through a small telescope, the cluster resolves into dozens of stars arranged in curving chains and rows against a rich background, making it one of the finest open clusters for winter observing.

Contains several hundred stars spanning 28 light-years across at a distance of 2,800 light-years, with an age of approximately 150 million years.