HL Tau 76 explained

HL Tau 76 should not be confused with HL Tauri.

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,^[1] 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.^[2] Like other DAV white dwarfs, its variability arises from non-radial gravity wave pulsations within itself.^{[3] , § 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.^[4]

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.^[1] 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.^[5] It was then included in the 57th name-list of variable stars and given the variable star designation V441 Tauri.^[6] The unusual designation HL Tau 76 continues to be used by most authors.^[7]

Notes and References

1. 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 . 1961BOTT....3...35H.
2. 1968ApJ...153..151L . A New Short-Period Blue Variable . Landolt . Arlo U. . The Astrophysical Journal . 1968 . 153 . 151 . 10.1086/149645 . free .
3. 1990RPPh...53..837K . Physics of white dwarf stars . Koester . D. . Chanmugam . G. . Reports on Progress in Physics . 1990 . 53 . 7 . 837 . 10.1088/0034-4885/53/7/001 . 250915046 .
4. 2006A&A...446..237D . Whole Earth telescope observations of the ZZ Ceti star HL Tau 76 . Dolez . N. . Vauclair . G. . Kleinman . S. J. . Chevreton . M. . Fu . J. N. . Solheim . J. -E. . González Perez . J. M. . Ulla . A. . Fraga . L. . Kanaan . A. . Reed . M. . Kawaler . S. . O'Brien . M. S. . Metcalfe . T. S. . Nather . R. E. . Sanwal . D. . Klumpe . E. W. . Mukadam . A. . Wood . M. A. . Ahrens . T. J. . Silvestri . N. . Sullivan . D. . Sullivan . T. . Jiang . X. J. . Xu . D. W. . Ashoka . B. N. . Leibowitz . E. . Ibbetson . P. . Ofek . E. . Kilkenny . D. . Astronomy and Astrophysics . 2006 . 446 . 1 . 237 . 10.1051/0004-6361:20053149 . 1 . free .
5. 1969ApJ...158..281G . 10.1086/150191 . The Lowell Suspect White Dwarfs . Greenstein, Jesse L. . Astrophysical Journal . 158 . 281 . October 1969 .
6. 57th Name-List of Variable Stars . 1 . Kukarkin . B. V. . Kholopov . P. N. . Perova . N. B. . Information Bulletin on Variable Stars . 480 . 1 . October 1970 . 1 . 1970IBVS..480....1K .
7. 2021MNRAS.500.4703C . 10.1093/mnras/staa3572 . 2011.06918 . Asteroseismology of the DAV star R808 . Chen, Y. H. . Shu, H. . Monthly Notices of the Royal Astronomical Society . 500 . 4 . 4703–4709 . January 2021 . free .