Astronomy:ESO 439-26
From HandWiki
Short description: White dwarf star
| Observation data Epoch J2000.0 Equinox (celestial coordinates) | |
|---|---|
| Constellation | Hydra |
| Right ascension | 11h 39m 03.1036679378s[1] |
| Declination | −28° 52′ 16.627821186″[1] |
| Apparent magnitude (V) | 20.52[2] |
| Characteristics | |
| Spectral type | DC9[2] |
| U−B color index | 1.03[3] |
| B−V color index | 0.64[3] |
| R−I color index | 1.14[3] |
| Astrometry | |
| Proper motion (μ) | RA: -397.767 ±0.481[4] mas/yr Dec.: + 36.869 ±0.441[4] mas/yr |
| Parallax (π) | 9.7390 ± 0.5007[4] mas |
| Distance | 330 ± 20 ly (103 ± 5 pc) |
| Absolute magnitude (MV) | 15.46[2][4] |
| Details | |
| Mass | 0.499397 ±0.150755[5] M☉ |
| Radius | 0.0126[6] R☉ |
| Luminosity | 1.15 ×10−5 [3] L☉ |
| Surface gravity (log g) | 7.866295 ±0.282184[5] cgs |
| Temperature | 4,672.65±274.68[5] K |
| Other designations | |
Ruiz 439-26, WD 1136-286[1] | |
| Database references | |
| SIMBAD | data |
ESO 439-26 was considered the least luminous white dwarf known.[2][7] Located 140 light years away from the Sun, it is roughly 10 billion years old and has a temperature of 4560 Kelvin. Thus, despite being classified as a "white dwarf", it would actually appear yellowish in color.[8]
This finding is however based on a too large parallax. Gaia measurement of the parallax shows a more distant source and therefore an absolute magnitude of MG=15.0 mag. For example the white dwarf WD J2147–4035 has MG=17.7 mag, making this white dwarf less luminous.[9][5] The updated MV is 15.46, using the Gaia parallax[4] and the apparent V-magnitude from Ruiz et al. (see formulae at the article absolute magnitude).[2]
References
- ↑ 1.0 1.1 1.2 "Ruiz 439-26". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Ruiz+439-26.
- ↑ 2.0 2.1 2.2 2.3 2.4 María Teresa Ruiz; P. Bergeron; S. K. Leggett; Claudio Anguita (1995). "The Extremely Low Luminosity White Dwarf ESO 439-26". The Astrophysical Journal 455. doi:10.1086/309845. Bibcode: 1995ApJ...455L.159R. https://iopscience.iop.org/article/10.1086/309845/fulltext/5601.text.html.
- ↑ 3.0 3.1 3.2 3.3 Bergeron, P.; Leggett, S. K.; Ruiz, María Teresa (April 2001). "Photometric and Spectroscopic Analysis of Cool White Dwarfs with Trigonometric Parallax Measurements". Astrophysical Journal Supplement Series 133 (2): 413–449. doi:10.1086/320356. Bibcode: 2001ApJS..133..413B.
- ↑ 4.0 4.1 4.2 4.3 4.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940 Gaia DR3 record for this source at VizieR.
- ↑ 5.0 5.1 5.2 5.3 Gentile Fusillo, N. P.; Tremblay, P. -E.; Cukanovaite, E.; Vorontseva, A.; Lallement, R.; Hollands, M.; Gänsicke, B. T.; Burdge, K. B. et al. (2021-12-01). "A catalogue of white dwarfs in Gaia EDR3". Monthly Notices of the Royal Astronomical Society 508 (3): 3877–3896. doi:10.1093/mnras/stab2672. ISSN 0035-8711. Bibcode: 2021MNRAS.508.3877G.
- ↑ Ruiz, Maria Teresa; Bergeron, P.; Leggett, S. K.; Anguita, Claudio (1995-12-01). "The Extremely Low Luminosity White Dwarf ESO 439-26". The Astrophysical Journal 455: L159. doi:10.1086/309845. ISSN 0004-637X. https://ui.adsabs.harvard.edu/abs/1995ApJ...455L.159R.
- ↑ "The Faintest Known White Dwarf". 1 March 1996. https://www.noao.edu/noao/noaonews/mar96/art3.html.
- ↑ Kaler, James B. (May 7, 2006). The Hundred Greatest Stars. Springer Science & Business Media. ISBN 9780387216256. https://books.google.com/books?id=jmoQBwAAQBAJ&q=ESO+439-26&pg=PA75.
- ↑ Elms, Abbigail K.; Tremblay, Pier-Emmanuel; Gänsicke, Boris T.; Koester, Detlev; Hollands, Mark A.; Gentile Fusillo, Nicola Pietro; Cunningham, Tim; Apps, Kevin (2022-12-01). "Spectral analysis of ultra-cool white dwarfs polluted by planetary debris". Monthly Notices of the Royal Astronomical Society 517 (3): 4557–4574. doi:10.1093/mnras/stac2908. ISSN 0035-8711. Bibcode: 2022MNRAS.517.4557E.
 |  |
