|   | 
Credit & Copyright: Peter Tuthill   
(Sydney U.)  
  
Explanation:
What could cause a nebula to appear square?  
  
No one is quite sure.  
  
The hot star system known as   
MWC 922, however, appears to be imbedded in a nebula with just such a shape.    
  
The above image combines   
infrared exposures from the   
Hale Telescope on   
Mt. Palomar in   
California, and the   
Keck-2 Telescope on   
Mauna Kea in   
Hawaii.    
  
 A leading progenitor hypothesis for the   
square nebula is that the central star or stars   
somehow expelled cones of gas during a late   
developmental stage.   
  
For MWC 922,   
these cones happen to incorporate nearly   
right angles   
and be visible from the sides.    
  
Supporting evidence for the   
cone   
hypothesis includes radial spokes in the image that might run along the cone walls.  
  
Researchers speculate that the cones viewed from   
another angle would appear similar to the gigantic rings of   
supernova 1987A,   
possibly indicating that a star in MWC 922 might one day itself explode in a similar   
supernova.  
  
| January February March April May June July August September October November December | 
 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day
Publications with keywords: nebula
Publications with words: nebula
See also:
