| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 12 00 44.461 |
| Declination | –10° 26′ 46.06″ |
| Apparent magnitude (V) | 5.54 |
| Characteristics | |
| Spectral type | G8 IV + M4V |
| U−B color index | +0.43 |
| B−V color index | +0.76 |
| Astrometry | |
| Radial velocity (Rv) | 0.14±0.14 km/s |
| Proper motion (μ) | RA: 82.841 mas/yr Dec.: −482.807 mas/yr |
| Parallax (π) | 78.7565 ± 0.1206 mas |
| Distance | 41.41 ± 0.06 ly (12.70 ± 0.02 pc) |
| Absolute magnitude (MV) | 5.15±0.009 |
| Orbit | |
| Period (P) | 48.5 yr |
| Semi-major axis (a) | 10.4 AU |
| Eccentricity (e) | 0.29 |
| Inclination (i) | 35° |
| Details | |
| A | |
| Mass | 0.98 M☉ |
| Radius | 1.01 R☉ |
| Surface gravity (log g) | 4.43 cgs |
| Temperature | 5,538 K |
| Metallicity | 0.18 dex |
| Rotational velocity (v sin i) | 4.5 km/s |
| Age | 8.48 Gyr |
| B | |
| Mass | 0.21+0.03 −0.02 M☉ |
| Other designations | |
| BD−09°3413, GJ 454, HD 104304, HIP 58576, HR 4587, SAO 157041, G 24 G. Virginis, LTT 4476 | |
| Database references | |
| SIMBAD | data |
HD 104304 (24 G. Virginis) is a binary star system in the zodiac constellation Virgo. It has a combined apparent visual magnitude of 5.54, making it visible to the unaided eye under suitable viewing conditions. The system is located at a distance of 41 light-years from the Sun based on parallax measurements. The primary component has a stellar classification of G8 IV, which means that this is a subgiant star that has left the main sequence and has begun to evolve into a giant star. The secondary is a faint red dwarf star with a class of M4V.
In 2007, a candidate planet was announced orbiting the primary. This was updated in 2010 when two independent papers announced the discovery of a common proper motion companion red dwarf. It is believed to have a mass of 0.21 M☉ and spectral type of M4V although the spectrum has not been directly observed. The most likely orbit has a period of 48.5 years and an eccentricity of 0.29. Further measurement will be needed to determine whether the star has a planetary companion, but further companions with masses above 83 MJ and separated by at least 3.9 au can be ruled out.
References
- ^ 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.
- ^ Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
- ^ Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992
- ^ Schnupp, C.; et al. (June 2010), "Discovery of a stellar companion to the nearby solar-analogue HD 104304", Astronomy and Astrophysics, 516: A21, arXiv:1005.0620, Bibcode:2010A&A...516A..21S, doi:10.1051/0004-6361/201014740, S2CID 54984741
- Park, Sunkyung; et al. (2013), "Wilson-Bappu Effect: Extended to Surface Gravity", The Astronomical Journal, 146 (4): 73, arXiv:1307.0592, Bibcode:2013AJ....146...73P, doi:10.1088/0004-6256/146/4/73, S2CID 119187733.
- ^ Takeda, Genya; et al. (2007). "Structure and Evolution of Nearby Stars with Planets. II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog". The Astrophysical Journal Supplement Series. 168 (2): 297. arXiv:astro-ph/0607235. Bibcode:2007ApJS..168..297T. doi:10.1086/509763. S2CID 18775378.
- Hearnshaw, J. B. (1972), "The abundances of the elements in the oldest disk stars", Memoirs of the Royal Astronomical Society, 77: 55, Bibcode:1972MmRAS..77...55H
- Schröder, C.; et al. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo" (PDF), Astronomy and Astrophysics, 493 (3): 1099–1107, Bibcode:2009A&A...493.1099S, doi:10.1051/0004-6361:200810377
- "HD 104304". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-10-11.
- Tanner, Angelle M.; et al. (2010), "A High-Contrast Imaging Survey of SIM Lite Planet Search Targets", Publications of the Astronomical Society of the Pacific, 122 (896): 1195, arXiv:1007.4315, Bibcode:2010PASP..122.1195T, doi:10.1086/656481, S2CID 118459054.
- Schneider, Jean, "Star : HD 104304", Extrasolar Planets Encyclopaedia, archived from the original on November 13, 2007, retrieved 2011-12-21
