PSR B1828−11

PSR B1828-11 (also known as PSR B1828-10^[2]) is a pulsar approximately 10,000 light-years away in the constellation of Scutum. The star exhibits variations in the timing and shape of its pulses: this was at one stage interpreted as due to a possible planetary system in orbit around the pulsar, though the model required an anomalously large second period derivative of the pulse times.^[3] The planetary model was later discarded in favour of precession effects as the planets could not cause the observed shape variations of the pulses.^[4][5] While the generally accepted model is that the pulsar is a neutron star undergoing free precession,^[6] a model has been proposed that interprets the pulsar as a quark star undergoing forced precession due to an orbiting "quark planet".^[7] The entry for the pulsar on SIMBAD lists this hypothesis as being controversial.^[2]

PSR B1828-11

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Scutum
Right ascension	18h 30m 47.75s
Declination	−10° 59′ 10.8″
Distance	10,000 ly (3,200[1] pc)
Spectral type	Pulsar
Other designations
PSR J1830-1059, PSR B1828-10
Database references
SIMBAD	data