WD 0343+247
WD 0343+247 is a white dwarf in the ecliptic constellation of Taurus. It was discovered in 1997 when examination of photographs taken for a survey of brown dwarfs in the Pleiades revealed a faint star with high proper motion. It is one of the coolest white dwarfs known, with an effective temperature estimated to be approximately 3,800 K, equivalent to a spectral type of M0.[7] Although referred to as WD 0346+246 in the discovery paper, it is more correctly designated WD 0346+247.[3]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Taurus | 
| Right ascension | 03h 46m 46.517s[1] | 
| Declination | +24° 56′ 02.67″[1] | 
| Apparent magnitude (V) | 19.0[2] | 
| Characteristics | |
| Evolutionary stage | white dwarf | 
| Spectral type | DX13[3] | 
| U−B color index | +0.30[2] | 
| B−V color index | +1.44[2] | 
| Astrometry | |
| Proper motion (μ) | RA: 520.177[1] mas/yr Dec.: −1,157.434[1] mas/yr | 
| Parallax (π) | 25.2941 ± 0.2085 mas[1] | 
| Distance | 129 ± 1 ly (39.5 ± 0.3 pc) | 
| Absolute magnitude (MV) | 16.80[3] | 
| Details | |
| Mass | 0.553±0.031[4] M☉ | 
| Radius | 0.011±0.001[4] R☉ | 
| Luminosity | 0.000048[4] L☉ | 
| Temperature | 4,197±83[5] K | 
| Age | 11.49±1.51[4] Gyr | 
| Other designations | |
| Database references | |
| SIMBAD | data | 
Recent studies using NASA's Spitzer Space Telescope and MDM Observatory's 2.4-meter telescope (near Tucson, Arizona, USA) shows that this white dwarf (together with another one: SDSS J110217.48+411315.4) has a low (for white dwarfs) surface temperature between 3,700 and 3,800 K due to it being 11 to 12 billion years old.[5]
References
    
- 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.
- Lépine, Sébastien; Shara, Michael M. (March 2005). "A Catalog of Northern Stars with Annual Proper Motions Larger than 0.15" (LSPM-NORTH Catalog)". The Astronomical Journal. 129 (3): 1483–1522. arXiv:astro-ph/0412070. Bibcode:2005AJ....129.1483L. doi:10.1086/427854. S2CID 2603568.
-  McCook, G. P.; Sion, E. M. (2014). "Entry for WD 0642-166". A Catalogue of Spectroscopically Identified White Dwarfs. Bibcode:2016yCat....102035M. {{cite book}}:|journal=ignored (help)
- Torres, Santiago; Rebassa-Mansergas, Alberto; Camisassa, María E.; Raddi, Roberto (2021). "The Gaia DR2 halo white dwarf population: The luminosity function, mass distribution, and its star formation history". Monthly Notices of the Royal Astronomical Society. 502 (2): 1753. arXiv:2101.03341. Bibcode:2021MNRAS.502.1753T. doi:10.1093/mnras/stab079.
- "12-Billion-Year-Old White-Dwarf Stars Only 100 Light-Years Away".
- "WD 0343+247". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved November 5, 2007.
- Hambly, N. C.; Smartt, S. J.; Hodgkin, S. T. (1997). "WD 0346+246: A Very Low Luminosity, Cool Degenerate in Taurus". The Astrophysical Journal. 489. Bibcode:1997ApJ...489L.157H. doi:10.1086/316797. S2CID 118643795.