Calvera (X-ray source)

For other uses, see Calvera (disambiguation).

In astronomy, Calvera (also known as 1RXS J141256.0+792204^[4]) is an X-ray source in the constellation Ursa Minor, identified in 2007 as an isolated neutron star.^[5][6] It is one of the hottest^[7] and closest of its kind to Earth.^[8]

Calvera

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Ursa Minor
Right ascension	14h 12m 55.867s[1]
Declination	+79° 22′ 03.895″[1]
Characteristics
Evolutionary stage	Neutron star
Astrometry
Proper motion (μ)	RA: 78.1[2] mas/yr Dec.: 8.0[2] mas/yr
Distance	≤2000[1] pc
Details[1]
Rotation	59.199071070 ms
Age	285,000 years
Other designations
PSR J1412+7922, RX J1412.9+7922, 1RXS J141256.0+792204[3]
Database references
SIMBAD	data

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;^[9] it is very likely its supernova remnant.^[2]