This is a mosaic of two 22 minute exposures with an ST-1301E CCD camera thru Kopernik's 20-inch F/8.1 Ritchey Chretien Cassegrain telescope working at F/5. It was taken with an h-alpha filter isolating the light of glowing hydrogen gas.
NGC 281, the Pacman Nebula:
NGC 281 is an emission nebula (glowing Hydrogen H II region) in the Constellation of Cassiopeia. 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 nebula is a star formation region. Prominent features in the Kopernik image above include the diffuse emission nebula, large lanes of obscuring gas and dust, and dense knots of dust and gas in which stars may still be forming. These small dark knots are called Bok globules (see ). The Kopernik image was taken using an h-alpha filter that brings out the glowing hydrogen. The NGC 281 system lies about 10 thousand light years distant.
IC 1590, an Open Star Cluster:
IC 1590 is the Open Star Cluster visible in the upper right of the Kopernik image above. It has formed only in the last few million years. The brightest member of this cluster is actually a multiple-star system shining light that helps ionize the Pacman nebula's gas, causing the glow visible throughout.
Classification: Emission Nebula
Classification: Open Star Cluster
George Normandin, KAS
December 25th, 2011