Rare Lone Neutron Star Found Nearby

F4_W_weasel sends us to the BBC for news of the eighth lone neutron star ever discovered. It has no associated supernova remnant, binary companion, or radio pulsations. It's in our stellar neighborhood, at most 1,000 light years away. The object emits all its radiation (as far as wa can detect with current instruments) in X rays. The object is called Calvera, after the bad guy in The Magnificent Seven — which is itself the collective nickname for the seven such objects previously known.

Raw data

[ELProphet]

He compared a catalogue of 18,000 X-ray sources from the German-American Rosat satellite, which operated from 1990 to 1999, with catalogues of objects that appeared in visible light, infrared light, and radio waves.

Makes me wonder how much data has been colected, but not analyzed, and what other astronomical wonders and oddities will be found when that data is analyzed.

Re:How certain are they about the radio noise?

[AJWM]

I think the "new discovery" part is the "without supernova remnant". Aren't most pulsars embedded in their supernova remnants?

May be an age thing. If the object is young enough that the remnant is still nearby and visible, it's young enough that it hasn't yet shed a lot of energy through its pulsar (etc) emissions, and vice versa. An old neutron star whose remnant nebula is long gone is likely to be a slow, feeble pulsar at best.