The Gum Nebula—A new kind of astronomical object

SEP 01, 1971

Did radiation from a supernova explosion ionize this huge mass of hydrogen? Four theories propose ways that the Nebula could have been created by energy from the supernova.

DOI: 10.1063/1.3022929

Stephen P. Maran

John C. Brandt

Theodore P. Stecher

The Gum Nebula is seen on photographs of the southern skies as an extensive region of ionized hydrogen that surrounds the well known Vela X supernova remnant. One of the largest objects in our galaxy, the Nebula was first recognized as a single emission complex by Colin S. Gum during the 1950’s. Until recently, astronomers assumed that it was a “Strömgren sphere,” excited by ultraviolet light from the hot stars gamma Velorum and zeta Puppis within it. This excitation process accounts for the Orion Nebula and other H‐II regions. The synchrotron and thermal bremsstrahlung mechanisms account for the radiation from supernova remnants, such as the Crab Nebula and Vela X; these objects consist of rapidly expanding matter ejected by the supernova explosions.

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More about the Authors

Stephen P. Maran. NASA—Goddard Space Flight Center, Greenbelt, Maryland.

John C. Brandt. NASA—Goddard Space Flight Center, Greenbelt, Maryland.

Theodore P. Stecher. Joint Institute for Laboratory Astrophysics, Boulder, Colorado.