Daily Archives: February 22, 2015

C46, NGC 2261, Hubble Variable Nebula


NGC 2261 (also known as Hubble’s Variable Nebula or Caldwell 46) is a variable nebula located in the constellationMonoceros. It is illuminated by the star R Monocerotis (R Mon), which is not directly visible itself. NGC 2261 was imaged as Palomar Observatory’s Hale Telescope’s first light by Edwin Hubble on January 26, 1949, some 20 years after the Palomar Observatory project began in 1928. One explanation proposed for the variability is that dense clouds of dust near R Mon periodically block the illumination from the star.

Imaging telescopes or lenses: Celestron C11 Celestron
Imaging cameras: 40D Canon
Mounts: CGEM Celestron
Guiding cameras: Orion Star Shooter
Software: Deep Sky Stacker,  photoshop
Resolution: 775×568
Dates: March 8, 2013
Frames: 25×60″
Integration: 0.4 hours
Avg. Moon age: 25.48 days
Avg. Moon phase: 17.43%
RA center: 99.794 degrees
DEC center: 8.759 degrees
Pixel scale: 1.583 arcsec/pixel
Orientation: -115.932 degrees
Field radius: 0.211 degrees
Locations: Leesburg home, Leesburg , Florida, United States
Author: AlBroxton
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