SSSPM J1549−3544

SSSPM J1549-3544 is a star in the constellation Lupus with high proper motion. It was initially found to have high proper motion in a 2003 survey of images taken by the optical SuperCOSMOS Sky Surveys and by the near-infrared sky surveys 2MASS and DENIS. It was then thought to be a cool white dwarf close to the Sun.^[3] However, more detailed spectroscopic observations in 2005 appear to show that it is not a white dwarf, but a high-velocity halo metal-poor subdwarf.^[2]

SSSPM J1549−3544

Observation data Epoch J2000      Equinox J2000
Constellation	Lupus
Right ascension	15h 48m 40.172s[1]
Declination	−35° 44′ 26.17″[1]
Apparent magnitude (V)	14.78[2]
Characteristics
Spectral type	sdK5[2]
Astrometry
Proper motion (μ)	RA: −597.714[1] mas/yr Dec.: −535.841[1] mas/yr
Parallax (π)	10.4127±0.0214 mas[1]
Distance	313.2 ± 0.6 ly (96.0 ± 0.2 pc)
Absolute magnitude (MV)	9.5
Details
Radius	0.30[1] R☉
Luminosity	0.02[1] L☉
Surface gravity (log g)	5.0[1] cgs
Temperature	3,956[1] K
Metallicity [Fe/H]	−1.28[1] dex
Other designations
SSSPM J1549-3544, 2MASS J15484023-3544254
Database references
SIMBAD	data