Geminga
Within the Gemini constellation there is a neutron star: Geminga. Its name is both a contraction of "Gemini gamma-ray source" and the Milanese Latin dialect for "not there". The nature of this curious stellar object was quite unknown for 20 years after its discovery by the SAS-2 satellite. Finally, in March 1991 the ROSAT satellite detected a periodicity of 0.237 s in soft x-ray emission. Thus, it is supposed that Geminga is a sort of neutron star: the decaying core of a behemoth star that went supernova about 100,000 years ago.
This nearby explosion may be responsible for the low density of the interstellar medium in the immediate vicinity of the Solar System. This low-density area is known as the Local Bubble.
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Categories: Astronomy | Astronomy stubs