XTE J1650−500

XTE J1650−500 is a binary system containing a stellar-mass black hole candidate and 2000–2001 transient binary X-ray source located in the constellation Ara. In 2008, it was claimed that this black hole had a mass of 3.8±0.5 solar masses,^[4] which would have been the smallest found for any black hole; smaller than GRO 1655−40, the then known smallest of 6.3 M_☉.^[5] However, this claim was subsequently retracted;^[3] the more likely mass is 5–10 solar masses.

XTE J1650-500

Artist's impression of XTE J1650−500
Observation data Epoch J2000      Equinox J2000
Constellation	Ara[1]
Right ascension	16h 50m 00.98s[2]
Declination	−49° 57′ 43.6″[2]
Characteristics
Spectral type	K2V[2]
Astrometry
Distance	3300±700[3] pc
Details
Black hole
Mass	9.7±1.6[3] M☉
Other designations
INTREF 720
Database references
SIMBAD	data

The location of XTE J1650−500 (circled in red)

The binary period of the black hole and its companion is 0.32 days.^[6]

See also

• Stellar black hole