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ET Virginis

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ET Virginis
Image
Image
Location of ET Virginis (circled in red)
Observation data
Epoch J2000      Equinox J2000
Constellation Virgo
Right ascension 14h 10m 50.48706s[1]
Declination −16° 18′ 07.3105″[1]
Apparent magnitude (V) 4.8 to 5.0[2]
Characteristics
Evolutionary stage AGB[3]
Spectral type M2 IIIa[4]
U−B color index +1.72[5]
Variable type SRB[2]
Astrometry
Radial velocity (Rv)+18.58±0.56[6] km/s
Proper motion (μ) RA: +3.277[1] mas/yr
Dec.: −10.804[1] mas/yr
Parallax (π)5.8655±0.2552 mas[1]
Distance560 ± 20 ly
(170 ± 7 pc)
Absolute magnitude (MV)−0.81[7]
Details
Mass3.24[8] M☉
Radius83[9] R☉
Luminosity963[1] L☉
Temperature3,899[1] K
Metallicity [Fe/H]−0.21±0.06[10] dex
Rotational velocity (v sin i)2.3±0.9[11] km/s
Other designations
ET Vir, BD−15°3817, HD 123934, HIP 69269, HR 5301, SAO 158401[12]
Database references
SIMBADdata

ET Virginis is a single,[13] red-hued star in the equatorial constellation of Virgo. It can be viewed with the naked eye, having an apparent visual magnitude of about five. Based upon an annual parallax shift of 5.9 mas,[1] it is located 560 light years away. It is moving further from the Earth with a heliocentric radial velocity of +18.6 km/s,[6] having come within 177 ly of the Sun around 6.3 million years ago.[7]

Image
A light curve for ET Virginis, plotted from data published by Tabur et al. (2009)[14]

This is an evolved red giant star with a stellar classification of M2 IIIa.[4] It is a semiregular variable star of subtype SRB with a magnitude that ranges from a high of 4.80 down to 5.00.[2] The measured angular diameter of this star, after correcting for limb darkening, is 4.79±0.34 mas.[15] At its estimated distance, this yields a physical size of 83 times the radius of the Sun.

In 1971, N. R. Stokes announced that the star, then called HD 123934, is a "quasi-periodic" variable star.[16] It received its variable star designation, ET Virginis, in 1972.[17]

ET Vir Pulsation Cycles[14]
Period (Days) 22.623.836.437.639.848.8259.1
Amplitude (mag.) 0.0210.0230.0180.0270.0210.0190.032

This star was part of the obsolete constellation Noctua, the owl.[18]

References

[edit]
  1. 1 2 3 4 5 6 7 8 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. 1 2 3 Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  3. ↑ McDonald, I.; De Beck, E.; Zijlstra, A. A.; Lagadec, E. (2018). "Pulsation-triggered dust production by asymptotic giant branch stars". Monthly Notices of the Royal Astronomical Society. 481 (4): 4984. arXiv:1809.07965. Bibcode:2018MNRAS.481.4984M. doi:10.1093/mnras/sty2607.
  4. 1 2 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373, S2CID 123149047.
  5. ↑ Soubiran, C.; et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics, 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247, S2CID 118362423.
  6. 1 2 de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  7. 1 2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
  8. ↑ Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022), "Stellar and substellar companions from Gaia EDR3", Astronomy & Astrophysics, 657: A7, arXiv:2109.10912, Bibcode:2022A&A...657A...7K, doi:10.1051/0004-6361/202142146, S2CID 237605138.
  9. ↑ Stassun, Keivan G.; et al. (2019-10-01), "The Revised TESS Input Catalog and Candidate Target List", The Astronomical Journal, 158 (4): 138, arXiv:1905.10694, Bibcode:2019AJ....158..138S, doi:10.3847/1538-3881/ab3467, hdl:1721.1/124721, ISSN 0004-6256, S2CID 166227927.
  10. ↑ Gáspár, András; et al. (August 2016), "The Correlation between Metallicity and Debris Disk Mass", The Astrophysical Journal, 826 (2): 14, arXiv:1604.07403, Bibcode:2016ApJ...826..171G, doi:10.3847/0004-637X/826/2/171, S2CID 119241004, 171.
  11. ↑ Zamanov, R. K.; et al. (October 2008), "Rotational velocities of the giants in symbiotic stars - III. Evidence of fast rotation in S-type symbiotics", Monthly Notices of the Royal Astronomical Society, 390 (1): 377–382, arXiv:0807.3817, Bibcode:2008MNRAS.390..377Z, doi:10.1111/j.1365-2966.2008.13751.x, S2CID 118697261.
  12. ↑ "HD 123934". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 16 August 2018.
  13. ↑ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  14. 1 2 Tabur, V.; et al. (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, S2CID 15358380.
  15. ↑ Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
  16. ↑ Stokes, N. R. (1971). "The variability of M-stars". Monthly Notices of the Royal Astronomical Society. 152 (2): 165–195. Bibcode:1971MNRAS.152..165S. doi:10.1093/mnras/152.2.165. Retrieved 12 December 2024.
  17. ↑ Kukarkin, B. V.; Kholopov, P. N.; Kukarkina, N. P.; Perova, N. B. (September 1972). "58th Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 717: 165. Bibcode:1971MNRAS.152..165S. doi:10.1093/mnras/152.2.165. Retrieved 12 December 2024.
  18. ↑ Hoffmann, Susanne M; Mamajek, Eric; Azkarrula, Youla. "Noctua". All Skies Encyclopaedia. IAU Working Group on Star Names. Retrieved 25 May 2026.
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