NGC 7510 (also OCL 256) is a magnitude +7.9 open cluster located about 11,400 light-years away in the constellation Cepheus.
The open cluster was discovered by German-British astronomer William Herschel using a 47.5 cm (18.7 inch) f/13 speculum reflector at Windsor Road in Slough, Berkshire, on the 3rd November 1787.
NGC 7510 is a bright young cluster about 10 million years old, situated in the Perseus Arm, in a region particularly rich in large complexes of molecular clouds and groups of young massive stars. Its components are the most massive spectral class B and A stars. The cluster is located in the south-eastern part of Cepheus, just north of the midpoint of the line joining the stars Zeta Cephei and Beta Cassiopeiae. Through a pair of 10x50 binoculars it is seen as a small and faint elongated fuzzy object centred on a magnitude 9 star. With a 100mm telescope it is resolved into a dozen components of twelfth magnitude. Larger apertures allow better resolution of its stars. Long-exposure photographs show components of the Sh2-157 nebula. The declination of this cluster favours observers in the northern hemisphere, with it becoming circumpolar at high latitudes. From the southern hemisphere it is quite low and not observable at latitudes far from the tropical zone. The best time to observe this object is in the evening sky between July and December.
Right Ascension 23h 11m 03.8s, Declination 60° 34' 15"
