M38 - STARFISH CLUSTER

Messier 38 (NGC 1912) is a large open cluster in the constellation Auriga, located approximately 4,200 light-years from Earth. It is the third member of the famous Auriga cluster trio along with M36 and M37. M38 contains roughly 100 to 150 stars spread across a diameter of about 25 light-years and shines at a combined apparent magnitude of about 7.4, making it the faintest of the three Auriga Messier clusters. The cluster is estimated to be around 220 million years old and contains a mix of blue-white main-sequence stars and a few yellow giants. M38 was first recorded by Giovanni Battista Hodierna before 1654 and was independently cataloged by Messier in 1764. The cluster is sometimes called the Starfish Cluster due to the pattern of its brightest stars, which form a rough cross or starfish shape that is apparent at low to moderate magnification. This distinctive pattern, combined with the cluster's relatively loose and scattered distribution, gives M38 a character quite different from the concentrated richness of nearby M37. Through binoculars, M38 appears as a faint, grainy patch of light. A small telescope reveals the cross-shaped pattern of brighter stars with fainter members scattered throughout. Just 30 arcminutes to the south of M38 lies the smaller and more compact open cluster NGC 1907, which at a distance of about 4,200 light-years may be physically associated with M38. The two clusters make an attractive pair in a wide-field eyepiece. M38 spans about 21 arcminutes, roughly two-thirds the apparent diameter of the full Moon, and is best appreciated at moderate magnification.

Contains 100 to 150 stars within 25 light-years diameter at a distance of 4,200 light-years, with an estimated age of 220 million years.