HL Tau 76 is a variable white dwarf star of the DAV (or ZZ Ceti) type. It was observed by G. Haro and W. J. Luyten in 1961,[8][9] and was the first variable white dwarf discovered when, in 1968, Arlo U. Landolt found that it varied in brightness with a period of approximately 749.5 seconds, or 12.5 minutes.[9] Like other DAV white dwarfs, its variability arises from non-radial gravity wave pulsations within itself.[10], § 7. Later observation and analysis has found HL Tau 76 to pulsate in over 40 independent vibrational modes, with periods between 380 seconds and 1390 seconds.[11]

HL Tau 76
A white-light light curve light curve for HL Tau 76, adapted from Warner and Nather (1972)[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Taurus
Right ascension 04h 18m 56.638s[2]
Declination +27° 17′ 48.31″[2]
Apparent magnitude (V) 14.1–15.28[3]
Spectral type DA4.3[4]
B−V color index 0.2[5]
Variable type DAV (ZZ Ceti)[3]
Proper motion (μ) RA: 62.600[2] mas/yr
Dec.: −72.819[2] mas/yr
Parallax (π)20.7244 ± 0.0338 mas[2]
Distance157.4 ± 0.3 ly
(48.25 ± 0.08 pc)
Absolute magnitude (MV)11.69[4]
Mass0.575±0.005[6] M
Radius0.0162[6] R
Luminosity0.00389[6] L
Surface gravity (log g)7.8[7] cgs
Temperature11,375±30[6] K
Other designations
EGGR 265, V411 Tau, WD 0416+272[5]
Database references

The designation HL Tau 76 derives from the discovery of this star as a white dwarf, when it was described as Taurus no.76 in a publication authored by Guillermo Haro and Willem Jacob Luyten.[8] The exact designation HL Tau 76 was then used in subsequent papers, including one giving the star its designation EGGR 265 where it was noted to be variable.[12] It was then included in the 57th name-list of variable stars and given the variable star designation V441 Tauri.[13] The unusual designation HL Tau 76 continues to be used by most authors.[14]

Notes and referencesEdit

  1. ^ Warner, Brian; Nather, R. Edward (January 1972). "Observations of rapid blue variables-III. HL Tau-76". Monthly Notices of the Royal Astronomical Society. 156: 1–5. Bibcode:1972MNRAS.156....1W. doi:10.1093/mnras/156.1.1.
  2. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. ^ a b Combined General Catalogue of Variable Stars (GCVS), v. 4.2. CDS ID II/250.
  4. ^ a b Gianninas, A.; Bergeron, P.; Ruiz, M. T. (2011). "A Spectroscopic Survey and Analysis of Bright, Hydrogen-rich White Dwarfs". The Astrophysical Journal. 743 (2): 138. arXiv:1109.3171. Bibcode:2011ApJ...743..138G. doi:10.1088/0004-637X/743/2/138. S2CID 119210906.
  5. ^ a b "HL Tau 76". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved June 12, 2007.
  6. ^ a b c d Pech, D.; Vauclair, G.; Dolez, N. (2006). "Asteroseismological constraints on the structure of the ZZ Ceti star HL Tau 76". Astronomy and Astrophysics. 446 (1): 223. Bibcode:2006A&A...446..223P. doi:10.1051/0004-6361:20053150.
  7. ^ Gentile Fusillo, N. P.; Tremblay, P. -E.; Cukanovaite, E.; Vorontseva, A.; Lallement, R.; Hollands, M.; Gänsicke, B. T.; Burdge, K. B.; McCleery, J.; Jordan, S. (2021). "A catalogue of white dwarfs in Gaia EDR3". Monthly Notices of the Royal Astronomical Society. 508 (3): 3877. arXiv:2106.07669. Bibcode:2021MNRAS.508.3877G. doi:10.1093/mnras/stab2672.
  8. ^ a b Haro, G.; Luyten, W. J. (1961). "Nueva estrella enana blanca en las nubes obscuras del Toro". Boletín de los Observatorios de Tonantzintla y Tacubaya. 3: 35. Bibcode:1961BOTT....3...35H.
  9. ^ a b Landolt, Arlo U. (1968). "A New Short-Period Blue Variable". The Astrophysical Journal. 153: 151. Bibcode:1968ApJ...153..151L. doi:10.1086/149645.
  10. ^ Koester, D.; Chanmugam, G. (1990). "Physics of white dwarf stars". Reports on Progress in Physics. 53 (7): 837. Bibcode:1990RPPh...53..837K. doi:10.1088/0034-4885/53/7/001.
  11. ^ Dolez, N.; et al. (2006). "Whole Earth telescope observations of the ZZ Ceti star HL Tau 76". Astronomy and Astrophysics. 446 (1): 237. Bibcode:2006A&A...446..237D. doi:10.1051/0004-6361:20053149.
  12. ^ Greenstein, Jesse L. (October 1969). "The Lowell Suspect White Dwarfs". Astrophysical Journal. 158: 281. Bibcode:1969ApJ...158..281G. doi:10.1086/150191.
  13. ^ Kukarkin, B. V.; et al. (October 1970). "57th Name-List of Variable Stars". Information Bulletin on Variable Stars. 480 (1). Bibcode:1970IBVS..480....1K.
  14. ^ Chen, Y. H.; Shu, H. (January 2021). "Asteroseismology of the DAV star R808". Monthly Notices of the Royal Astronomical Society. 500 (4): 4703–4709. arXiv:2011.06918. Bibcode:2021MNRAS.500.4703C. doi:10.1093/mnras/staa3572.