aka NGC 1912 or Starfish Cluster, is an open cluster of stars in the constellation of Auriga.
It was discovered by Giovanni Batista Hodierna before 1654 and independently found by Le Gentil in 1749.
Open cluster M36 and M37, also discovered by Hodierna, are often grouped together with M38.
Distance is about 3,480 ly away from Earth. The open cluster NGC 1907 lies nearby on the sky, but the two are most likely just experiencing a fly-by, having originated in different parts of the galaxy.

The cluster's brightest stars form a pattern resembling the Greek letter Pi or, according to Webb, an "oblique cross".

At its distance of 1066 pc., its angular diameter of about 20 arc minutes corresponds to about 4.0 parsecs (13 light years), similar to that of its more distant neighbor M37. It is of intermediate age at about 290 million years.[2] From the population of about 100 stars,[7] this open cluster features a prominent yellow giant with the apparent magnitude +7.9 and spectral type G0 as its brightest member.