Daily Archives: October 31, 2014

NGC 281


NGC 281 is an H II region in the constellation of Cassiopeia and part of the Perseus Spiral Arm. It includes the open cluster IC 1590, the multiple star HD 5005, and several Bok globules. Colloquially, NGC 281 is also known as the Pacman Nebula for its resemblance to the video game character.

The nebula was discovered in August 1883 by E. E. Barnard, who described it as “a large faint nebula, very diffuse.” The multiple star HD 5005, also called \beta1, was discovered by S. W. Burnham. It consists of an 8th-magnitude primary with four companions at distances between 1.4 and 15.7 seconds of arc. There has been no appreciable change in this quintuple system since the first measurements were made in 1875.

The nebula is visible in amateur telescopes from dark sky locations. In his book Deep Sky Wonders, Walter Scott Houston describes the appearance of the nebula in small telescopes

Imaging telescopes or lenses: Altair Astro Wave Series 115 F7 ED Triplet APO
Imaging cameras: Canon EOS 600Da
Mounts: SkyWatcher NEQ6 pro Goto
Guiding telescopes or lenses: Orion Mini 50mm Guide Scope
Guiding cameras: Starshoot Autoguider
Focal reducers: Altair Astro PlanoStar 3″ Flattener
Software: Astrotortilla, DeepSky Stacker 3.3.3 Deep Sky Stacker 3.3.3, Photoshop CS5
Resolution: 4906×3193
Frames: 70×600″
Integration: 11.7 hours
RA center: 13.234 degrees
DEC center: 56.578 degrees
Pixel scale: 1.093 arcsec/pixel
Orientation: 81.918 degrees
Field radius: 0.889 degrees

Astrophotography of the day of  SPONLI, 31.10.2014