WD 1337+705

WD 1337+705

Artist's Impression of WD 1337+705 accreting both rocky and icy material
Credit: NASA, ESA, Joseph Olmsted (STScI)
Observation data
Epoch J2000      Equinox J2000
Constellation Ursa Minor
Right ascension 13h 38m 50.4781s[1]
Declination +70° 17′ 07.6414″[1]
Apparent magnitude (V) 12.773
Characteristics
Spectral type DA2.4[2]
Astrometry
Proper motion (μ) RA: −402.093 ± 0.078[1] mas/yr
Dec.: −24.608 ± 0.068[1] mas/yr
Parallax (π)37.7083 ± 0.0422 mas[1]
Distance86.49 ± 0.10 ly
(26.52 ± 0.03 pc)
Absolute magnitude (MV)10.56[2]
Details
Mass0.59[2] M☉
Luminosity0.03[3] L☉
Temperature21290 K[2] K
Other designations
WD 1337+705, EG 102, HIP 66578, LTT 18341
Database references
SIMBADdata

WD 1337+705 (G238-44) is a star in the constellation Ursa Minor. Shining with an apparent magnitude of 12.8, it is white dwarf 0.59 times as massive as the Sun.[2] It is 86.5 light-years distant from Earth.[1] It has 3% of the Sun's luminosity.[3]

In 1997, Jay Holberg and colleagues discovered magnesium in its spectrum, which suggests that it has some low mass companion or accretion of material happening as the star's temperature is not hot enough for its intrinsic emission.[4] Despite this, no direct evidence for a circumstellar disc, such as an infrared excess, has come to light.[5]

In 2022 a team of researchers found that the metal-pollution of this white dwarf is unusual. The presence of iron in the atmosphere indicates that an iron-rich minor planet was accreted. This object formed close to the star with a Mercury-like composition. The presence of nitrogen on the other hand shows that an icy Kuiper Belt Object was accreted as well. This nitrogen is usually stored in ices, such as N2 and ammonia. KBOs are also rich in other ices (H2O, CO, CO2) containing carbon and oxygen, which are also present in this white dwarf. Other detected elements are Magnesium, Aluminium, Silicon, Phosphorus, Sulfur and Calcium. The accreted KBO was 7.1 times more massive than the Mercury-like object. The white dwarf formed from a main-sequence star around 50 Myrs ago. Simulations have shown that it is possible for both main-belt asteroids and KBOs to be delivered within the first 100 Myrs.[6]

See also

References

  1. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  2. ^ a b c d e Gianninas, A.; Bergeron, P.; Ruiz, M. T. (2011). "A Spectroscopic Survey and Analysis of Bright, Hydrogen-rich White Dwarfs". The Astrophysical Journal. 743 (2): 27. arXiv:1109.3171. Bibcode:2011ApJ...743..138G. doi:10.1088/0004-637X/743/2/138. S2CID 119210906. 138.
  3. ^ a b Bannister, N. P.; Barstow, M. A.; Holberg, J. B.; Bruhweiler, F. C. (2003). "Circumstellar features in hot DA white dwarfs". Monthly Notices of the Royal Astronomical Society. 341 (2): 477–95. arXiv:astro-ph/0301204. Bibcode:2003MNRAS.341..477B. doi:10.1046/j.1365-8711.2003.06409.x. S2CID 122754617.
  4. ^ Holberg, Jay; Barstow, M.A.; Green, Elizabeth M. (1997). "The Discovery of Mg II λ4481 in the White Dwarf EG 102: Evidence for Ongoing Accretion". The Astrophysical Journal. 474 (2): L127 – L130. Bibcode:1997ApJ...474L.127H. doi:10.1086/310446.
  5. ^ Dickinson, N. J.; Barstow, M. A.; Welsh, B. Y.; Burleigh, M.; Farihi, J.; Redfield, S.; Unglaub, K. (2012). "The origin of hot white dwarf circumstellar features". Monthly Notices of the Royal Astronomical Society. 423 (2): 1397–1410. arXiv:1203.5226. Bibcode:2012MNRAS.423.1397D. doi:10.1111/j.1365-2966.2012.20964.x. S2CID 119212643.
  6. ^ Johnson, Ted M.; Klein, Beth L.; Koester, D.; Melis, Carl; Zuckerman, B.; Jura, M. (2022-12-01). "Unusual Abundances from Planetary System Material Polluting the White Dwarf G238-44". The Astrophysical Journal. 941 (2): 113. arXiv:2211.02673. Bibcode:2022ApJ...941..113J. doi:10.3847/1538-4357/aca089. ISSN 0004-637X.