SSSPM J1549-3544

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]
Distance313.2 ± 0.6 ly
(96.0 ± 0.2 pc)
Absolute magnitude (MV)9.5
Details
Radius0.30[1] R☉
Luminosity0.02[1] L☉
Surface gravity (log g)5.0[1] cgs
Temperature3,956[1] K
Metallicity [Fe/H]−1.28[1] dex
Other designations
SSSPM J1549-3544, 2MASS J15484023-3544254
Database references
SIMBADdata

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]

  1. ^ a b c d e f g h i j Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c Farihi, J.; Wood, P. R.; Stalder, B. (2005). "SSSPM J1549-3544 is Not a White Dwarf". The Astrophysical Journal. 627 (1): L41–L43. arXiv:astro-ph/0505525. Bibcode:2005ApJ...627L..41F. doi:10.1086/432158. S2CID 10645235.
  3. ^ Scholz, R. -D; Lehmann, I.; Matute, I.; Zinnecker, H. (2004). "The nearest cool white dwarf (D ∼4 pc), the coolest M-type subdwarf (SdM9.5), and other high proper motion discoveries". Astronomy and Astrophysics. 425: 519–527. arXiv:astro-ph/0406457. Bibcode:2004A&A...425..519S. doi:10.1051/0004-6361:20041059. S2CID 9352481.