38 Virginis
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 53m 11.1564s[1] |
| Declination | −03° 33′ 11.1482″[1] |
| Apparent magnitude (V) | 6.11 |
| Characteristics | |
| Spectral type | F6V[2] |
| B−V color index | 0.49[2] |
| Astrometry | |
| Proper motion (μ) | RA: −262.638±0.113[1] mas/yr Dec.: −3.853±0.100[1] mas/yr |
| Parallax (π) | 30.0702 ± 0.0541 mas[1] |
| Distance | 108.5 ± 0.2 ly (33.26 ± 0.06 pc) |
| Details | |
| Mass | 1.18 ± 0.12[2] M☉ |
| Radius | 1.45 ± 0.07[2] R☉ |
| Luminosity | 3.48[note 1] L☉ |
| Temperature | 6557 ± 96[2] K |
| Metallicity [Fe/H] | 0.07[2] dex |
| Age | 1.9+0.6 −0.7[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
38 Virginis is an F-type main sequence star in the constellation of Virgo. It is around 108 light years distant from the Earth.[2][1]
Nomenclature[edit]
The name 38 Virginis derives from the star being the 38th star in order of right ascension catalogued in the constellation Virgo by Flamsteed in his star catalogue. The designation b of 38 Virginis b derives from the order of discovery and is given to the first planet orbiting a given star, followed by the other lowercase letters of the alphabet.[4] In the case of 38 Virginis, only one was discovered, which was designated b.[2]
Stellar characteristics[edit]
38 Virginis is an F-type main sequence star that is approximately 118% the mass of and 145% the radius of the Sun. It has a temperature of 6557 K and is about 1.9 billion years old. In comparison, the Sun is about 4.6 billion years old[5] and has a temperature of 5778 K.[6]
The star is metal-rich, with a metallicity ([Fe/H]) of 0.07 dex, or 117% the solar amount. Its luminosity (L☉) is 3.48 times that of the Sun.
A companion star is cataloged in the CCDM at a separation of half an arcsecond.[7]
Planetary system[edit]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | 4.51 ± 0.5 MJ | 1.82 ± 0.07 | 825.9 ± 6.2 | 0.03 ± 0.04 | — | — |
The star is known to host one exoplanet, 38 Virginis b, discovered in 2016. This planet has a relatively low eccentricity out of any long-period giant exoplanet discovered, with an eccentricity of 0.03. The planet has a mass of around 4.5 times that of the planet Jupiter.[2] Its orbit very likely puts it and any moons it may have in the habitable zone of its star.[citation needed]
Notes[edit]
- ^ From , where is the luminosity, is the radius, is the effective surface temperature and is the Stefan–Boltzmann constant.
References[edit]
- ^ a b c d e f 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 d e f g h i j k Borgniet, S.; et al. (2017). "Extrasolar planets and brown dwarfs around AF-type stars. IX. The HARPS southern sample". Astronomy and Astrophysics. 599. A57. arXiv:1608.08257. Bibcode:2017A&A...599A..57B. doi:10.1051/0004-6361/201628805. S2CID 118723455.
- ^ "38 Virginis". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-10-19.
- ^ Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). "On the naming convention used for multiple star systems and extrasolar planets". arXiv:1012.0707 [astro-ph.SR].
- ^ Fraser Cain (16 September 2008). "How Old is the Sun?". Universe Today. Retrieved 19 February 2011.
- ^ Fraser Cain (15 September 2008). "Temperature of the Sun". Universe Today. Retrieved 19 February 2011.
- ^ J. Dommanget; et al. (February 2002), Catalog of Components of Double & Multiple Stars, Observations et Travaux, Societe Astronomique de France
