WD 2359−434

Last updated
WD 2359−434
Gliese 915 and Earth.png
Size of WD 2359−434 in comparison with Earth. On the left is Earth, on the right is WD 2359-434.
Observation data
Epoch J2000 [1]        Equinox J2000 [1]
Constellation Phoenix
Right ascension 00h 02m 10.72420s [2]
Declination −43° 09′ 55.3906″ [2]
Apparent magnitude  (V)12.76 [3]
Characteristics
Spectral type DAP5.8 [4]
Apparent magnitude  (B)13.12 [1]
Apparent magnitude  (V)12.76 [3]
Apparent magnitude  (RKC)12.82 [5]
Apparent magnitude  (IKC)12.66 [5]
Apparent magnitude  (J)12.60 ± 0.03 [5]
Apparent magnitude  (H)12.43 ± 0.02 [5]
Apparent magnitude  (KS)12.45 ± 0.02 [5]
Astrometry
Radial velocity (Rv)-58.8 ± 10.8 [6] km/s
Proper motion (μ)RA: 613.785 mas/yr [2]
Dec.: -686.989 mas/yr [2]
Parallax (π)120.0143±0.0215  mas [2]
Distance 27.176 ± 0.005  ly
(8.332 ± 0.001  pc)
Absolute magnitude  (MV)13.39±0.03
Details [7]
Mass 0.83±0.02  M☉
Radius 0.0097±0.0001 [8]   R☉
Luminosity 4.37+0.42
−0.38×10−4  L☉
Surface gravity (log g)8.37±0.02  cgs
Temperature 8,506±122 [8]   K
Age 1.83±0.18 [note 1]   Gyr
Other designations
GJ 915, EG GR 165, L 362-81, LAWD 96, LFT 1849, LHS 1005, LP 988-88, LTT 9857, WD 2359-434, 2MASS J00021076-4309560 [1]
Database references
SIMBAD data
Phoenix constellation map.svg
Red pog.png
WD 2359−434
Location of WD 2359−434 in the constellation Phoenix

WD 2359-434 (Gliese 915, LHS 1005, L 362-81) is a nearby degenerate star (white dwarf) of spectral class DAP5.8, [4] the single known component of the system, located in the constellation Phoenix, the nearest star in this constellation.

Contents

Distance

Currently, the most accurate distance estimate of WD 2359−434 is a trigonometric parallax from Gaia DR3: [2] 120.0143±0.0215  mas , corresponding to a distance of 8.332±0.001  pc , or 27.176±0.005  ly . WD 2359−434 is the 13th closest white dwarf to the Sun. [9]

Physical parameters

WD 2359−434's mass is 0.85 ± 0.01 Solar masses, [5] its surface gravity is 108.39 ± 0.01 (2.45 · 108) cm·s −2, [5] or approximately 250,000 of Earth's, corresponding to a radius 6780 km, or 1.06 of Earth's.

WD 2359−434 is relatively hot and young white dwarf, its temperature is 8570 ± 50 K; [3] its cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star) is 1.82 ± 0.06 Gyr. [5] Gliese 518 should appear bluish-white, due temperature, comparable with that of A-type main sequence stars.

As all white dwarfs, WD 2359−434 is composed of very dense degenerate matter, its mean density is 1,300,000 g·cm −3, [5] [note 2] i.e. mass of one cubic millimetre of WD 2359−434 matter is 1.3 kg.

Unusually for a white dwarf star, WD 2359-434 has a weak, non-dipole magnetic field of 50,000 - 100,000 Gauss. [10]

Main sequence progenitor properties

As all degenerate stars, WD 2359−434 previously existed initially as main-sequence star and then as giant star, until all the thermonuclear fuel was exhausted, after which WD 2359−434 lost most of its mass. According to the 2010 thesis for the degree of Doctor of Science, [11] using Wood model D [12] initial–final mass relation and WD 2359−434's white dwarf mass value 0.97 ± 0.03  M☉ from Holberg et al. 2008, [3] its main sequence progenitor mass was 7.09 M☉. Using expression for pre-white dwarf lifetime 10 · (MMS/M☉)2.5 (Gyr), [12] was found WD 2359−434 main sequence age 0.07 Gyr.

White dwarf mass value 0.85 ± 0.01 M☉ from Subasavage et al. 2009, [5] in Wood model D yields MS (main sequence) mass 6.03 M☉, and MS lifetime 0.11 Gyr, corresponding to B-type main sequence star.

According to initial-final mass relation from Weidemann 2000 paper, [13] WD 2359−434's main sequence progenitor should have mass about 4.6 M☉ and lifespan 0.22 Gyr, and, again, should be of B spectral type. There are also other models.

See also

Notes

  1. ↑ White dwarf cooling age, i. e. age as degenerate star (not including lifetime as main sequence star and as giant star).
  2. ↑ From mass and surface gravity (assuming spherical shape).

References

  1. 1 2 3 4 "GJ 915 -- White Dwarf". Centre de Données astronomiques de Strasbourg . Retrieved 2011-11-03.
  2. 1 2 3 4 5 6 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.
  3. 1 2 3 4 Holberg, J. B.; Sion; Oswalt; McCook; Foran; Subasavage (2008). "A New Look at the Local White Dwarf Population" . The Astronomical Journal . 135 (4): 1225–1238. Bibcode:2008AJ....135.1225H. doi:10.1088/0004-6256/135/4/1225. S2CID   122855486.
  4. 1 2 Sion, Edward M.; Holberg; Oswalt; McCook; Wasatonic (2009). "The White Dwarfs within 20 Parsecs of the Sun: Kinematics and Statistics". The Astronomical Journal . 138 (6): 1681–1689. arXiv: 0910.1288 . Bibcode:2009AJ....138.1681S. doi:10.1088/0004-6256/138/6/1681. S2CID   119284418.
  5. 1 2 3 4 5 6 7 8 9 10 Subasavage, John P.; Jao; Henry; Bergeron; Dufour; Ianna; Costa; Mendez (2009). "THE SOLAR NEIGHBORHOOD. XXI. PARALLAX RESULTS FROM THE CTIOPI 0.9 m PROGRAM: 20 NEW MEMBERS OF THE 25 PARSEC WHITE DWARF SAMPLE". The Astronomical Journal . 137 (6): 4547–4560. arXiv: 0902.0627 . doi:10.1088/0004-6256/137/6/4547. S2CID   14696597.
  6. ↑ Pauli, E.-M.; Napiwotzki; Heber; Altmann & Odenkirchen (2006). "3D kinematics of white dwarfs from the SPY project. II". Astronomy and Astrophysics . 447 (1): 173–184. arXiv: astro-ph/0510494 . Bibcode:2006A&A...447..173P. doi:10.1051/0004-6361:20052730. S2CID   14250519. (see Table 8)
  7. ↑ Subasavage, John P.; et al. (July 2017), "The Solar Neighborhood. XXXIX. Parallax Results from the CTIOPI and NOFS Programs: 50 New Members of the 25 parsec White Dwarf Sample", The Astronomical Journal, 154 (1): 24, arXiv: 1706.00709 , Bibcode:2017AJ....154...32S, doi: 10.3847/1538-3881/aa76e0 , S2CID   119189852, 32.
  8. 1 2 Bédard, A.; et al. (2017), "Measurements of Physical Parameters of White Dwarfs: A Test of the Mass-Radius Relation", The Astrophysical Journal, 848 (1): 11, arXiv: 1709.02324 , Bibcode:2017ApJ...848...11B, doi: 10.3847/1538-4357/aa8bb6 , S2CID   119359723
  9. ↑ Reylé, Céline; Jardine, Kevin; Fouqué, Pascal; Caballero, Jose A.; Smart, Richard L.; Sozzetti, Alessandro (30 April 2021), "The 10 parsec sample in the Gaia era", Astronomy & Astrophysics , 650: A201, arXiv: 2104.14972 , Bibcode:2021A&A...650A.201R, doi:10.1051/0004-6361/202140985, S2CID   233476431 Data available at https://gruze.org/10pc/ Archived 12 March 2023 at the Wayback Machine
  10. ↑ Landstreet, J. D.; Bagnulo, S.; Valyavin, G.; Valeev, A. F. (2017), "Monitoring and modelling of white dwarfs with extremely weak magnetic fields", Astronomy & Astrophysics, 607: A92, arXiv: 1709.04099 , doi:10.1051/0004-6361/201731432, S2CID   119502643
  11. ↑ Matías Cristóbal Radiszcz Sotomayor, BINARIEDAD ESTELAR Y SUB-ESTELAR EN ENANAS BLANCAS CERCANAS
  12. 1 2 Wood, M. A. (1992). "Constraints on the age and evolution of the Galaxy from the white dwarf luminosity function". The Astrophysical Journal . 386: 539–561. Bibcode:1992ApJ...386..539W. doi: 10.1086/171038 .
  13. ↑ Weidemann, V. (2000). "Revision of the initial-to-final mass relation". Astronomy and Astrophysics . 363: 647–656. Bibcode:2000A&A...363..647W.
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