NGC 281
| Emission nebula | |
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| Data from NGC 281
 
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| The emission nebula NGC 281 recorded from Earth. The bright star in the middle is BD + 55 ° 191 (HD 5005). | |
| AladinLite | |
| Constellation | Cassiopeia | 
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Position  equinox : J2000.0 , epoch : J2000.0  | 
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| Right ascension | 00 h 52 m 25 s | 
| declination | + 56 ° 34 ′ | 
| Appearance
 
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| Apparent brightness (B-band) | 7.3 likes | 
| Angular expansion | 35 '× 30' | 
| Ionizing source | |
| designation | 
IC 1590 ,  BD + 55 ° 191 (HD 5005)  | 
| Type | Star clusters with  stars of the spectral class O5.5  | 
| Physical data
 
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| Affiliation | Milky Way | 
| distance | 9500 ly | 
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history
 
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| discovery | EE Barnard | 
| Date of discovery | November 16, 1881 | 
| Catalog names | |
| NGC 281 • IC 11 • LBN 616 • Ced 3 | |
NGC 281 is an emission nebula in the constellation Cassiopeia , 9500 light years from Earth . The fog is recorded in the index catalog as IC 11 and is colloquially referred to as Pac-Man fog because of its similarity to the well-known video game main character of the same name , especially in the English-speaking world . The open star cluster IC 1590 is embedded in NGC 281 , the stars of which are scattered around the center of the nebula and some of which stand out due to their X-rays . The brightest member of IC 1590, the multiple star system BD + 55 ° 191 (HD 5005), is the ionizing source of the nebula. The nebula also contains several Bok globules in which infrared imaging has shown signs of star formation. The molecular cloud , the ionized part of which is the emission nebula, can also be seen in infrared images .
NGC 281 was discovered on November 16, 1881 by the American astronomer Edward Emerson Barnard .
Close-up of a Bok globule in NGC 281 ( Hubble Space Telescope )
The X-ray radiation from the embedded IC 1590 cluster can be seen in violet in the image taken by the Chandra X-ray telescope .
The image from the Wide-Field Infrared Survey Explorer shows the molecular cloud, the ionized part of which can be seen as an emission nebula (blue, left above the center of the image).
Web links
- Hubble Space Telescope
 - Cassiopeia constellation
 - Astronomie.de
 - GoBlack
 - Portrait of NGC 281 - Astronomy Picture of the Day December 10, 2008.
 - NGC 281: The Pacman Nebula - Astronomy Picture of the Day of August 23, 2005 (English).
 - NGC 281: Cluster, Clouds, and Globules - Astronomy Picture of the Day of April 7, 2003.
 - Spektrum.de : Collection of amateur recordings
 - SIMBAD query
 - SEDS
 - NASA / IPAC Extragalactic Database
 
Individual evidence
Attention: The sorting key "NGC 0281" overwrites the previously used key "IC0011".