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