RX J1856.5−3754

RX J1856.5−3754

X-ray image of RX J1856.5−3754
Observation data Epoch 1996.7      Equinox J2000.0
Constellation	Corona Australis
Right ascension	18h 56m 35s
Declination	−37° 54′ 36″
Apparent magnitude (V)	~25.6
Details
Mass	${\displaystyle 1.5\pm 0.2}$ M☉
Radius	${\displaystyle 12.1_{-1.6}^{+1.3}}$ km
Age	1 Myr
Other designations
RX J185635−3754, 1ES 1853−37.9, 1RXS J185635.1−375433
Database references
SIMBAD	data

RX J1856.5−3754 (also called RX J185635−3754, RX J185635−375, and various other designations) is a neutron star in the constellation Corona Australis. At approximately 400 light-years from Earth, it is the closest neutron star discovered to date.