Astronomy:74 Virginis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Virgo |
| Right ascension | 13h 31m 57.88506s[1] |
| Declination | −06° 15′ 20.9419″[1] |
| Apparent magnitude (V) | 4.69±0.01[2] |
| Characteristics | |
| Spectral type | M2.5 III[3] |
| B−V color index | 1.606±0.035 |
| Astrometry | |
| Radial velocity (Rv) | +18.71±0.15[4] km/s |
| Proper motion (μ) | RA: −103.94[1] mas/yr Dec.: −43.87[1] mas/yr |
| Parallax (π) | 8.16 ± 0.19[1] mas |
| Distance | 400 ± 9 ly (123 ± 3 pc) |
| Absolute magnitude (MV) | −0.76[5] |
| Details[2] | |
| Mass | 1.40±0.12 M☉ |
| Radius | 78.38+1.98 −1.90 R☉ |
| Luminosity | 831.5±56.8 L☉ |
| Temperature | 3,500±46 K |
| Metallicity [Fe/H] | 0.00 dex |
| Age | 2.90±0.68 Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
74 Virginis is a single[7] star in the zodiac constellation of Virgo.[6] It is visible to the naked eye as a faint red-hued star with an apparent visual magnitude of 4.69.[2] The star is positioned near the ecliptic and thus is subject to lunar occultations.[8] The measured annual parallax of 8.16 mas[1] provides a distance estimate of around 400 light-years from the Sun. At that range, the visual magnitude of the star is diminished by an extinction of 0.46±0.02 due to interstellar dust.[2] It is moving further from the Earth with a heliocentric radial velocity of +19 km/s.[4]
This is an aging red giant star with a stellar classification of M2.5 III,[3] which indicates it has exhausted the hydrogen at its core and evolved away from the main sequence. It is a suspected variable star that may vary in brightness with an amplitude of 0.07 in magnitude.[9] The star is roughly 2.9 billion years old with 1.4 times the mass of the Sun and has expanded to around 78 times the Sun's radius. 74 Virginis is radiating 832 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 3,500 K.[2]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 2.4 Baines, Ellyn K. et al. (2018), "Fundamental Parameters of 87 Stars from the Navy Precision Optical Interferometer", The Astronomical Journal 155 (1): 30, doi:10.3847/1538-3881/aa9d8b, Bibcode: 2018AJ....155...30B.
- ↑ 3.0 3.1 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, Bibcode: 1989ApJS...71..245K
- ↑ 4.0 4.1 Famaey, B. et al. (2009), "Spectroscopic binaries among Hipparcos M giants,. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics 498 (2): 627–640, doi:10.1051/0004-6361/200810698, Bibcode: 2009A&A...498..627F.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 "74 Vir". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=74+Vir.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Antal, M. (1962), "Observations of occultations at the Observatory Skalnaté Pleso in the year 1961", Bulletin of the Astronomical Institute of Czechoslovakia 13: 164, Bibcode: 1962BAICz..13..164A.
- ↑ Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode: 2017ARep...61...80S.
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