38 Virginis
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12h 53m 11.3s[1] |
| Declination | −03° 33′ 11″[1] |
| Apparent magnitude (V) | 6.11 |
| Characteristics | |
| Spectral type | F6V[2] |
| B−V color index | 0.49[2] |
| Astrometry | |
| Parallax (π) | 30.55 ± 0.30[2] mas |
| Distance | 107 ± 1 ly (32.7 ± 0.3 pc) |
| Absolute magnitude (MV) | 6.11 |
| 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. To view it, binoculars or a telescope are necessary, as it is too faint to be visible to the naked eye. It is around 107 light years distant from the Earth.[2]
Nomenclature
The name 38 Virginis derives directly the star being catalogued as the 38th star discovered in the constellation Virgo. 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.[3] In the case of 38 Virginis, only one was discovered, which was designated b.[2]
Stellar characteristics
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[4] and has a temperature of 5778 K.[5]
The star is metal-rich, with a metallicity ([Fe/H]) of 0.07, 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.[6]
Planetary system
| 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 | — | ~1.05 RJ |
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. It's orbit very likely puts it and any moons it may have in the habitable zone of its star.
Notes
- ↑ From , where is the luminosity, is the radius, is the effective surface temperature and is the Stefan–Boltzmann constant.
References
- 1 2 "Notes for 38 Vir b". Extrasolar Planets Encyclopedia. Retrieved 18 September 2016.
- 1 2 3 4 5 6 7 8 9 10 11 Borgniet, Simon; Lagrange, Anne-Marie; Meunier, Nadège; Galland, Franck (2016). "Extrasolar planets and brown dwarfs around AF-type stars. IX. The HARPS southern sample". arXiv:1608.08257
[astro-ph.EP]. - ↑ 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
Coordinates: 
12h 53m 11.3s, −03° 33′ 11″