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WZ Doradus

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WZ Doradus
Location of WZ Doradus on the map (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Dorado
Right ascension 05h 07m 34.02686s[1]
Declination −63° 23′ 58.8474″[1]
Apparent magnitude (V) 5.20 - 5.32[2]
Characteristics
Evolutionary stage AGB[3]
Spectral type M3 III[4]
U−B color index +1.85[5]
B−V color index +1.65[5]
Variable type SRb[2]
Astrometry
Radial velocity (Rv)19.3±2.8[6] km/s
Proper motion (μ) RA: +13.210 mas/yr[1]
Dec.: −44.813 mas/yr[1]
Parallax (π)5.6282 ± 0.1116 mas[1]
Distance580 ± 10 ly
(178 ± 4 pc)
Absolute magnitude (MV)−1.00[7]
Details
Mass1.4[8] M
Radius88.3+6.6
−10.0
[9] R
Luminosity1,248±47[9] L
Surface gravity (log g)0.50[10] cgs
Temperature3,603±125[10] K
Other designations
21 G. Doradus[11], WZ Dor, CD−63°188, CPD−63°420, FK5 2389, GC 6314, HD 33684, HIP 23840, HR 1695, SAO 249198, TIC 55298910[12]
Database references
SIMBADdata

WZ Doradus (HD 33684; HR 1695; 21 G. Doradus) is a solitary red-hued variable star[13] located in the southern constellation Dorado. It has an average apparent magnitude of 5.21,[14] making it faintly visible to the naked eye under ideal conditions. Gaia DR3 parallax measurements imply a distance of 580 light-years[1] and it is currently receding with a heliocentric radial velocity of 19.3 km/s.[6] At its current distance, WZ Doradus is diminished by two-tenths of a magnitude due to interstellar extinction and it has an absolute magnitude of −1.00.[7]

HD 33684 was first observed to vary in brightness by astronomer P. M. Corben in 1971.[15] It was said to have an amplitude of 0.18 magnitudes. A year later, HD 33684 was given the variable star designation WZ Doradus.[16] It was again observed in 1973 by Olin J. Eggen and he noticed that it varied within 40 days.[17] A 1998 survey found no strong emissions indicating dust around the star.[18] Another survey also found no technetium in its spectrum.[19] WZ Doradus is a semiregular variable of subtype SRb that varies between 5.2 and 5.32 within an average period of 40 days.[2] Tabur et al. (2009) found two periods for the star after it was widely believed to only have one period.[20]

WZ Doradus variability periods[20]
Amplitude (mag) Period (days)
0.042 26.0
0.026 44.6
A light curve for WZ Doradus, plotted from data published by Tabur et al.[20]

WZ Doradus has a stellar classification of M3 III,[4] indicating that it is an evolved red giant. It is currently on the asymptotic giant branch,[3] generating energy via the fusion of hydrogen and helium shells around an inert carbon core. As a result of its evolved state, it has expanded to 88.3 times the radius of the Sun[9] and it now radiates 1,248 times the luminosity of the Sun[9] from its enlarged photosphere at an effective temperature of 3,603 K.[10]

References

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  1. ^ a b c d e 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.
  2. ^ a b c Samus’, N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N. (January 2017). "General catalogue of variable stars: Version GCVS 5.1". Astronomy Reports. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. eISSN 1562-6881. ISSN 1063-7729. S2CID 125853869.
  3. ^ a b Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". The Astronomical Journal. 104: 275. Bibcode:1992AJ....104..275E. doi:10.1086/116239. ISSN 0004-6256. S2CID 121672252.
  4. ^ a b Houk, N.; Cowley, A. P. (1975). University of Michigan Catalogue of two-dimensional spectral types for the HD stars: Declinations −90° to −53°. Vol. 1. Bibcode:1975mcts.book.....H.
  5. ^ a b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data. SIMBAD, Bibcode:1986EgUBV........0M
  6. ^ a b Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
  7. ^ a b Anderson, E.; Francis, Ch. (May 2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331–346. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. eISSN 1562-6873. ISSN 1063-7737. S2CID 119257644.
  8. ^ Kervella, Pierre; et al. (March 2019). "Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly". Astronomy & Astrophysics. 623: 23. arXiv:1811.08902. Bibcode:2019A&A...623A..72K. doi:10.1051/0004-6361/201834371. S2CID 119491061. A72.
  9. ^ a b c d 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.
  10. ^ a b c McDonald, I.; Zijlstra, A. A.; Watson, R. A. (15 June 2017). "Fundamental parameters and infrared excesses of Tycho–Gaia stars". Monthly Notices of the Royal Astronomical Society. 471 (1): 770–791. arXiv:1706.02208. Bibcode:2017MNRAS.471..770M. doi:10.1093/mnras/stx1433. eISSN 1365-2966. ISSN 0035-8711. S2CID 73594365.
  11. ^ Gould, Benjamin Apthorp (1878). "Uranometria Argentina : brillantez y posicion de las estrellas fijas, hasta la septima magnitud, comprendidas dentro de cien grados del polo austral : con atlas". Resultados del Observatorio Nacional Argentino. 1. Bibcode:1879RNAO....1.....G.
  12. ^ "V* WZ Dor". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved August 30, 2023.
  13. ^ Eggleton, P. P.; Tokovinin, A. A. (11 September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. eISSN 1365-2966. ISSN 0035-8711. S2CID 14878976.
  14. ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (March 2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H. ISSN 0004-6361. S2CID 17128864.
  15. ^ Corben, P. M. (April 1971). "Photoelectric Magnitudes and Colours for Bright Southern Stars". Monthly Notes of the Astronomical Society of South Africa. 30 (4): 37. Bibcode:1971MNSSA..30...37C. ISSN 0024-8266.
  16. ^ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (1 September 1972). "58th Name-List of Variable Stars". Information Bulletin on Variable Stars. 717: 1. Bibcode:1972IBVS..717....1K. ISSN 0374-0676.
  17. ^ Eggen, O. J. (September 1973). "The classification of intrinsic variables. IV. Very-small-amplitude, very-short-period red variables". The Astrophysical Journal. 184: 793. Bibcode:1973ApJ...184..793E. doi:10.1086/152371. eISSN 1538-4357. ISSN 0004-637X. S2CID 120021304.
  18. ^ Sloan, G. C.; Price, S. D. (December 1998). "The Infrared Spectral Classification of Oxygen-rich Dust Shells". The Astrophysical Journal Supplement Series. 119 (2). American Astronomical Society: 141–158. Bibcode:1998ApJS..119..141S. doi:10.1086/313156. ISSN 0067-0049. S2CID 53469543.
  19. ^ Lebzelter, Th.; Hron, J. (November 1999). "A search for Technetium in semiregular variables". Astronomy and Astrophysics. 351: 533–542. Bibcode:1999A&A...351..533L. ISSN 0004-6361. S2CID 17019103.
  20. ^ a b c Tabur, V.; Bedding, T. R.; Kiss, L. L.; Moon, T. T.; Szeidl, B.; Kjeldsen, H. (21 December 2009). "Long-term photometry and periods for 261 nearby pulsating M giants". Monthly Notices of the Royal Astronomical Society. 400 (4): 1945–1961. arXiv:0908.3228. Bibcode:2009MNRAS.400.1945T. doi:10.1111/j.1365-2966.2009.15588.x. eISSN 1365-2966. ISSN 0035-8711. S2CID 15358380.