This is a short Double Cluster ;-). The conditions were not really good. The moon was shining and clouds were crossing the field of view.
Nevertheless, a nice picture came out of it
.
Object description (wikipedia.org):
The
Double Cluster (also known as
Caldwell 14) consists of the
open clustersNGC 869 and
NGC 884 (often designated h Persei and χ (chi) Persei, respectively), which are close together in the constellation
Perseus.
Both visible with the naked eye, NGC 869 and NGC 884 lie at a distance of about 7,500 light years in the
Perseus Arm of the
Milky Waygalaxy.
NGC 869 has a mass of 4,700 solar masses and NGC 884 weighs in at 3,700 solar masses; both clusters are surrounded with a very extensive halo of stars, with a total mass for the complex of at least 20,000 solar masses.
They form the core of the
Perseus OB1 association of young hot stars.Based on their individual stars, the clusters are relatively young, both 14 million years old.
In comparison, the
Pleiades have an estimated age ranging from 75 million years to 150 million years.
There are more than 300 blue-white super-giant stars in each of the clusters. The clusters are also blueshifted, with NGC 869 approaching Earth at a speed of 39 km/s (24 mi/s) and NGC 884 approaching at a similar speed of 38 km/s (24 mi/s).
Their hottest main sequence stars are of spectral type B0. NGC 884 includes five prominent
red supergiant stars, all variable and all around 8th magnitude:
RS Persei, AD Persei, FZ Persei, V403 Persei, and V439 Persei.
Comments