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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 mas[2] |
| Distance | 560 ± 20 ly (170 ± 7 pc) |
| Absolute magnitude (MV) | −0.81[7] |
| Details | |
| Mass | 3.24[8] M☉ |
| Radius | 83[9] R☉ |
| Luminosity | 963[2] L☉ |
| Temperature | 3,899[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 | |
| Database references | |
| SIMBAD | data |
In 1971, N. R. Stokes announced that the star, then called HD 123934, is a "quasi-periodic" variable star.[14] It received its variable star designation, ET Virginis, in 1972.[15]
| 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.[16] At its estimated distance, this yields a physical size of 83 times the radius of the Sun.
References
edit- ^ a b 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.
- ^ a b c d e f g h 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.
- ^ a b c 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.
- ^ a b 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.
- ^ a b 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.
- ^ a b 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.
- ^ a b 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ "HD 123934". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 16 August 2018.
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.