Calvera (X-ray source)
In astronomy, Calvera (also known as 1RXS J141256.0+792204) is an X-ray source in the constellation Ursa Minor, identified in 2007 as an isolated neutron star. It is one of the hottest and closest of its kind to Earth. It is named after the villain in the 1960 film The Magnificent Seven, as it is the eighth such neutron star known within 500 parsecs of Earth, and the seven previously discovered isolated neutron stars are called 'The Magnificent Seven'. There is a ring of radio emission almost a degree in diameter, offset about 4′.9 from Calvera itself, which is possibly its supernova remnant. References

External links
 Universe Today, Closest Neutron Star Discovered 
Pennsylvania State University. Neutron stars
Ursa Minor
ROSAT objects
Stars with proper names