Caldwell 14 - Double Cluster
 
Date:
 
November 15, 2015
 
Location:
 
Landers, California USA
 
Telescope:
 
Explore Scientific ED127 Apo
 
Camera:
 
SBIG STF-8300M
 
Mount:
 
Astro-Physics Mach1GTO
 
Acquisition:
 
Maxim DL Pro 6
 
Filters:
 
Baader LRGB
 
Total Integration:
 
1.75 hours
 
Subexposures:
 
L: 60 x 60s (1x1)
R: 15 x 60s (2x2)
G: 15 x 60s (2x2)
B: 15 x 60s (2x2)
 
Calibration:
 
Darks: 30ea
Bias: 30ea
Flats: 30ea
 
The Double Cluster (also known as Caldwell 14) is the common name for the naked-eye open clusters NGC 869 and NGC 884 which are located close together in the constellation Perseus. These star clusters lie at a distance of 7,500 light years. NGC 869 has a mass of 3,700 solar masses and NGC 884 weighs in at 2,800 solar masses; however, later research has shown 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.

Based on their individual stars, the clusters are relatively young, both 12.8 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, both approaching Earth at a speed of 24 miles per second.