61 Virginis
61 Vir as seen with a 12.5" telescope with a field of view of 45.1 arcminutes | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 13h 18m 24.3s |
| Declination | −18° 18′ 40.3″ |
| Apparent magnitude (V) | 4.74 |
| Characteristics | |
| Spectral type | G5V |
| Apparent magnitude (B) | 5.45 |
| Apparent magnitude (J) | 3.334 |
| Apparent magnitude (H) | 2.974 |
| Apparent magnitude (K) | 2.956 |
| U−B color index | 0.26 |
| B−V color index | 0.71 |
| V−R color index | 0.37 |
| R−I color index | 0.33 |
| Variable type | None |
| Astrometry | |
| Radial velocity (Rv) | -8.2 km/s |
| Proper motion (μ) | RA: -1,069.90 mas/yr Dec.: -1,063.78 mas/yr |
| Parallax (π) | 117.35 ± 0.69 mas |
| Distance | 27.8 ± 0.2 ly (8.52 ± 0.05 pc) |
| Absolute magnitude (MV) | 5.07 |
| Details | |
| Mass | 0.95+0.04 −0.03 M☉ |
| Radius | 0.940+0.034 −0.029[1] R☉ |
| Luminosity | 0.85[2] L☉ |
| Surface gravity (log g) | 4.5[3] cgs |
| Temperature | 5,585[3] K |
| Metallicity | [3] |
| Rotation | <17 km/s. |
| Age | 6.1–6.6[4] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
| Exoplanet Archive | data |
| ARICNS | data |
61 Virginis is a G5V class star slightly less massive than the Sun (G2V), located about 27.8 light-years away in the constellation of Virgo. The composition of this star is nearly identical to the Sun and there is only a low level of activity in the stellar chromosphere.[3]
This star is rotating once every 29 days at the equator. The space velocity components of this star are U = –37.9, V = –35.3 and W = –24.7 km/s. 61 Vir is orbiting through the Milky Way galaxy at a distance of 6.9 kpc from the core, with an eccentricity of 0.15. It is believed to be a disk star with an estimated age of more than six billion years.[2][4]
61 Virginis (G5V) is the first well established main sequence yellow dwarf star very similar to the Sun with a potential Super-Earth,[1] though COROT-7 (a borderline orange dwarf) is arguably the first.
Planetary system
There was some evidence that it may have a jovian planet, but it seemed not to have a nearby massive companion.[5] A subsequent study also failed to find the large substellar companion (with 20 to 80 times the mass of Jupiter) or a Jupiter-class planet,[6] so it was a good candidate for possessing a family of terrestrial planets, with an orbit slightly smaller and a year slightly less than that of the Earth.
A survey of this star with the Spitzer Space Telescope revealed an excess of infrared radiation at a wavelength of 160 μm. This indicated the presence of a debris disk in orbit around the star. This disk was resolved at 70 μm, corresponding to an inner radius of 96 AU from the star. The outer radius is estimated as 195 AU and the total mass of the disk is 5 × 10−5 the mass of the Earth.[7]
On 14 December 2009, scientists announced the discovery of three planets with masses between 5 and 25 times that of Earth orbiting around 61 Virginis.[1][8] The three planets all orbit very near the star; when compared to the orbits of the planets in our solar system, all three would orbit inside the orbit of Venus. Additional data is needed to confirm the possibility of a fourth planet.[1]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥ 5.1±0.5 M🜨 | 0.050201±0.000005 | 4.2150±0.0006 | 0.12±0.11 | — | — |
| c | ≥ 18.2±1.1 M🜨 | 0.2175±0.0001 | 38.021±0.034 | 0.14±0.06 | — | — |
| d | ≥ 22.9±2.6 M🜨 | 0.476±0.001 | 123.01±0.55 | 0.35±0.09 | — | — |
See also
References
- ^ a b c d e Vogt, Steven; Wittenmyer; Paul Butler; Simon O'Toole; Henry; Rivera; Stefano Meschiari; Gregory Laughlin; Tinney (2009). "A Super-Earth and two Neptunes Orbiting the Nearby Sun-like star 61 Virginis". arXiv:0912.2599 [astro-ph.EP].
{{cite arXiv}}: Unknown parameter|accessdate=ignored (help); Unknown parameter|version=ignored (help) - ^ a b Porto de Mello, Gustavo; del Peloso, Eduardo F.; Ghezzi, Luan (2006). "Astrobiologically Interesting Stars Within 10 Parsecs of the Sun". Astrobiology. 6 (2): 3087ndash, 331. doi:10.1089/ast.2006.6.308. PMID 16689649.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b c d Perrin, M.-N.; Cayrel de Strobel, G.; Dennefeld, M. (1988). "High S/N detailed spectral analysis of four G and K dwarfs within 10 PC of the sun". Astronomy and Astrophysics. 191 (2): 237–247. Bibcode:1988A&A...191..237P.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ a b Mamajek, Eric E.; Hillenbrand, Lynne A. (2008). "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics". The Astrophysical Journal. 687 (2): 1264–1293. Bibcode:2008ApJ...687.1264M. doi:10.1086/591785.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - ^ Campbell et al., 1988, pages 904, 906, and 919
- ^ Cumming et al., 1999
- ^ Tanner, Angelle (2009). "Survey of Nearby FGK Stars at 160 μm with Spitzer". The Astrophysical Journal. 704 (1): 1097ndash, 116. doi:10.1088/0004-637X/704/1/109.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help); Unknown parameter|month=ignored (help) - ^ Tim Stephens (2009-12-14). "New planet discoveries suggest low-mass planets are common around nearby stars". UCSC News. UC Santa Cruz. Retrieved 2009-12-14.
External links
- 61 Virginis at SolStation
- Systemic Blog article with comparative map of orbits of 61 Vir b,c and d
- Aladin image of 61 Virginis
 | This main-sequence-star-related article is a stub. You can help Wikipedia by expanding it. |