TY Coronae Borealis

Last updated
TY Coronae Borealis
TYCrBLightCurve.png
A blue band light curve for TY Coronae Borealis, adapted from Bognár et al. (2019) [1]
Observation data
Epoch J2000.0       Equinox J2000.0
Constellation Corona Borealis
Right ascension 16h 01m 23.187s [2]
Declination +36° 48′ 34.29″ [2]
Apparent magnitude  (V)14.435±0.018 [3]
Characteristics
Evolutionary stage White dwarf
Spectral type DA4.4 [4]
Variable type ZZ Ceti [5]
Astrometry
Proper motion (μ)RA: 101.113 mas/yr [2]
Dec.: −545.353 mas/yr [2]
Parallax (π)30.4668±0.0187  mas [2]
Distance 107.05 ± 0.07  ly
(32.82 ± 0.02  pc)
Absolute magnitude  (MV)+11.81 [6]
Details
Mass 0.593±0.028 to 0.615+0.024
−0.025 [3]   M☉
Radius 0.0131±0.0014 [7]   R☉
Luminosity (1.83±0.03)×10−3 [8]   L☉
Surface gravity (log g)8.194 [9]   cgs
Temperature 11,000 [9]   K
Age 447 (white dwarf stage) [6]   Myr
Other designations
TY CrB, Ross 808, WD 1600+369, LTT 14769, NLTT 41782, 2MASS J16012317+3648351 [4]
Database references
SIMBAD data

TY Coronae Borealis, also known as Ross 808, is a white dwarf in the constellation Corona Borealis. It is 107 light-years distant from Earth, [2] and has a dim apparent magnitude of 14.4. [3]

It is a pulsating white dwarf of the DAV (ZZ Ceti) type. The variation in the blue band is of 0.14 magnitudes, over a period of 15 minutes. [5] It was confirmed as a variable star in 1976, and now has the variable-star designation TY Coronae Borealis. [10] Being of this variable class, it has been a target for asteroseismic analyses, in attempt to derive its physical properties such as mass, radius and gravity. [9] [11] [8] However, it seems estimations of the stellar mass derived for this star using asteroseismology had been overestimated. [3]

TY Coronae Borealis has around 0.6 times the mass of the Sun [3] and a tiny diameter of only 1.3% that of the Sun. [7] It is a dim star, with 0.2% of the Sun's luminosity. [8] It has an effective temperature of about 11,000  K, [9] have taken 450 million years to cool to its temperature. This is also its age as a white dwarf. [6]

References

  1. ↑ Bognár, Zs.; Paparó, M.; Sódor, Á.; Jenei, D. I.; Kalup, Cs.; Bertone, E.; Chavez-Dagostino, M.; Montgomery, M. H.; Gyõrffy, Á.; Molnár, L.; Ollé, H.; Pápics, P. I.; Plachy, E.; Verebélyi, E. (January 2019). "Wandering near the red edge: photometric observations of three cool ZZ Ceti stars". Monthly Notices of the Royal Astronomical Society. 482 (3): 4018–4031. arXiv: 1810.09711 . Bibcode:2019MNRAS.482.4018B. doi: 10.1093/mnras/sty2884 .
  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 5 Calcaferro, Leila M.; Córsico, Alejandro H.; Uzundag, Murat; Althaus, Leandro G.; Kepler, S. O.; Werner, Klaus (2024-11-01). "An analysis of spectroscopic, seismological, astrometric, and photometric masses of pulsating white dwarf stars". Astronomy & Astrophysics. 691: A194. arXiv: 2409.03896 . Bibcode:2024A&A...691A.194C. doi:10.1051/0004-6361/202450582. ISSN   0004-6361.
  4. 1 2 "TY CrB". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 5 December 2016.
  5. 1 2 Watson, Christopher (4 January 2010). "TY Coronae Borealis". AAVSO Website. American Association of Variable Star Observers . Retrieved 23 November 2014.
  6. 1 2 3 Limoges, M. -M.; Bergeron, P.; Lépine, S. (2015-08-01). "Physical Properties of the Current Census of Northern White Dwarfs within 40 pc of the Sun". The Astrophysical Journal Supplement Series. 219 (2): 19. arXiv: 1505.02297 . Bibcode:2015ApJS..219...19L. doi:10.1088/0067-0049/219/2/19. ISSN   0067-0049.
  7. 1 2 Bédard, A.; Bergeron, P.; Fontaine, G. (2017-10-05). "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 . ISSN   0004-637X.
  8. 1 2 3 Romero, A. D.; Córsico, A. H.; Althaus, L. G.; Kepler, S. O.; Castanheira, B. G.; Miller Bertolami, M. M. (2012-02-21). "Toward ensemble asteroseismology of ZZ Ceti stars with fully evolutionary models". Monthly Notices of the Royal Astronomical Society. 420 (2): 1462–1480. arXiv: 1109.6682 . Bibcode:2012MNRAS.420.1462R. doi: 10.1111/j.1365-2966.2011.20134.x . ISSN   0035-8711.
  9. 1 2 3 4 Chen, Y H; Shu, H (2021-02-01). "Asteroseismology of the DAV star R808". Monthly Notices of the Royal Astronomical Society. 500 (4): 4703–4709. doi: 10.1093/mnras/staa3572 . ISSN   0035-8711.
  10. ↑ McGraw, John T.; Robinson, Edward L. (1976). "High-speed photometry of luminosity-variable DA dwarfs: R808, GD 99, and G 117-B15A". Astrophysical Journal Letters. 205: L155-58. Bibcode:1976ApJ...205L.155M. doi:10.1086/182112.
  11. ↑ Bischoff-Kim, Agnès; Bell, Keaton J. (2024-07-12). "Constraints from Parallaxes and Average Period Spacings in the Asteroseismic Study of Eight Hydrogen-atmosphere Pulsating White Dwarfs". The Astrophysical Journal. 970 (1): 27. Bibcode:2024ApJ...970...27B. doi: 10.3847/1538-4357/ad4edc . ISSN   0004-637X.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.