Within the Gemini constellation there lies a neutron star: Geminga. (du-du-du~u~u~umm!). 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 sattelite. Finally, in the 3rd month of the one-thousand nine-hundred ninety-first year the ROSAT satellite detected a periodicity of .237 sec 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.
See [[[1]]] for more info.