A new candidate for "local space nasty that can cause us damage in 2012" has emerged:

The density creates such high pressure at the core that quarks sometimes could be squeezed out of their usually tight groupings, and become free. This liberation, called quark deconfinement, would turn a normal neutron star into a “quark star.” Astronomers have already found a few objects that they theorize may be quark stars. But Rachid Ouyed, an astrophysicist at the University of Calgary in Canada, and a group of colleagues also propose that their formation could release massive amounts of energy, producing a type of implosion they call a “quark nova.” That, they add, may help explain certain hitherto mysterious cosmic blasts. “Quark stars are the only place we would expect to see quarks ranging free in nature,” said Ouyed. His group plans to present findings of their theoretical studies June 5 at the American Astronomical Society meeting in Calgary. Most likely to become quark stars are fast-spinning neutron stars with masses between 1.5 and 1.8 times that of our sun, they calculated. Thus one in every hundred known neutron stars could actually be a quark star. Quark stars probably look like normal neutron stars except they don’t emit certain radio waves, the researchers argue. This peculiarity has already been noted in a class of neutron stars described as “radio-quiet,” about seven of which are known. Thus, these may be quark stars, the scientists say.

And so, is there a local candidate. Yes there is, RX J1856.5-3754 (also called RX J185635-3754, RX J185635-375, and various other designations). Discovered in 1992, it is between 150 & 450 light years away. Next closest is Geminga (Gemini gamma-ray source), a neutron star approximately 552 light-years away in the constellation Gemini.

Source: World Science