Astronomy:ET Virginis

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Short description: Evolved red giant star in the constellation Virgo
ET Virginis
ETVirLightCurve.png
A light curve for ET Virginis, plotted from data published by Tabur et al. (2009)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Virgo
Right ascension  14h 10m 50.48706s[2]
Declination −16° 18′ 07.3105″[2]
Apparent magnitude (V) 4.910[3]
Characteristics
Spectral type M2 IIIa[4]
U−B color index +1.72[3]
Variable type SRB[5]
Astrometry
Radial velocity (Rv)+18.58±0.56[6] km/s
Proper motion (μ) RA: +3.277[2] mas/yr
Dec.: −10.804[2] mas/yr
Parallax (π)5.8655 ± 0.2552[2] mas
Distance560 ± 20 ly
(170 ± 7 pc)
Absolute magnitude (MV)−0.81[7]
Details
Mass3.24[8] M
Radius83[9] R
Luminosity963[2] L
Temperature3,899[2] 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 4.91.[3] Based upon an annual parallax shift of 5.9 mas,[2] 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]

ET Vir Pulsation Cycles[1]
Period (Days) 22.6 23.8 36.4 37.6 39.8 48.8 259.1
Amplitude (mag.) 0.021 0.023 0.018 0.027 0.021 0.019 0.032

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.[5] The measured angular diameter of this star, after correcting for limb darkening, is 4.79±0.34 mas.[14] At its estimated distance, this yields a physical size of 83 times the radius of the Sun.

References

  1. 1.0 1.1 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, doi:10.1111/j.1365-2966.2009.15588.x, Bibcode2009MNRAS.400.1945T. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  3. 3.0 3.1 3.2 Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode2010A&A...515A.111S. 
  4. 4.0 4.1 Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K. 
  5. 5.0 5.1 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, doi:10.1134/S1063772917010085, Bibcode2017ARep...61...80S. 
  6. 6.0 6.1 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, doi:10.1051/0004-6361/201219219, A61, Bibcode2012A&A...546A..61D. 
  7. 7.0 7.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  8. Kervella, Pierre; Arenou, Frédéric; Thévenin, Frédéric (2022), "Stellar and substellar companions from Gaia EDR3", Astronomy & Astrophysics 657: A7, doi:10.1051/0004-6361/202142146, Bibcode2022A&A...657A...7K. 
  9. Stassun, Keivan G. et al. (2019-10-01), "The Revised TESS Input Catalog and Candidate Target List", The Astronomical Journal 158 (4): 138, doi:10.3847/1538-3881/ab3467, ISSN 0004-6256, Bibcode2019AJ....158..138S. 
  10. Gáspár, András et al. (August 2016), "The Correlation between Metallicity and Debris Disk Mass", The Astrophysical Journal 826 (2): 14, doi:10.3847/0004-637X/826/2/171, 171, Bibcode2016ApJ...826..171G. 
  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, doi:10.1111/j.1365-2966.2008.13751.x, Bibcode2008MNRAS.390..377Z. 
  12. "HD 123934". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+123934. 
  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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  14. Richichi, A. et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode2005A&A...431..773R.