Caldwell 49 - Rosette Nebula
 
Date:
 
February 23 - March 4, 2016
 
Location:
 
Landers, California USA
 
Telescope:
 
Explore Scientific ED127 Apo
 
Camera:
 
SBIG STF-8300M
 
Mount:
 
Astro-Physics Mach1GTO
 
Acquisition:
 
Maxim DL Pro 6
 
Filters:
 
Astrodon 5nm Ha
Baader RGB
 
Total Integration:
 
11.67 hours
 
Subexposures:
 
Ha: 40 x 600s (1x1)
R: 20 x 300s (2x2)
G: 20x 300s (2x2)
B: 20 x 300s (2x2)
 
Calibration:
 
Darks: 30ea
Bias: 30ea
Flats: 30ea
 
The Rosette Nebula (also known as Caldwell 49) is a large, spherical, H II region located near one end of a giant molecular cloud in the Monoceros region of the Milky Way Galaxy. The open cluster NGC 2244 (Caldwell 50) is closely associated with the nebulosity, the stars of the cluster having been formed from the nebula's matter.

The cluster and nebula lie at a distance of some 5,000 light-years from Earth and measure roughly 50 light years in diameter. The radiation from the young stars excites the atoms in the nebula, causing them to emit radiation themselves producing the emission nebula we see. The mass of the nebula is estimated to be around 10,000 solar masses.

Altogether, approximately 2,500 young stars lie in this star-forming complex, including the massive O-type stars HD 46223 and HD 46150, which are primarily responsible for blowing the ionized bubble. Most of the ongoing star-formation activity is occurring in the dense molecular cloud to the south east of the bubble.