orbit of the pulsar and white dwarf had been measured, giving an estimate of the mass of the third object that was too small for it to be a star. The conclusion that the third object was a planet was announced by Stephen Thorsett and his collaborators in 1993. See also PSR B1257+12 Delta Trianguli Pulsar planet References External links SolStation: PSR B1620−26 SPACE: Oldest Known World Conjures Prospect of Ancient Life Binary stars Pulsars White dwarfs Scorpius (constellation) 2 Planetary systems with one confirmed planet