French
Deutsch7 Boötis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Boötes |
| Right ascension | 13h 53m 12.93033s[1] |
| Declination | +17° 55′ 58.3282″[1] |
| Apparent magnitude (V) | 5.71[2] |
| Characteristics | |
| Evolutionary stage | Hertzsprung gap[2] |
| Spectral type | G5 III[2] |
| B−V color index | 0.845[3] |
| Astrometry | |
| Radial velocity (Rv) | −11.00±0.18[1] km/s |
| Proper motion (μ) | RA: −34.842[1] mas/yr Dec.: +5.092[1] mas/yr |
| Parallax (π) | 5.5236 ± 0.0776 mas[1] |
| Distance | 590 ± 8 ly (181 ± 3 pc) |
| Details[2] | |
| Mass | 4.0±0.7 M☉ |
| Radius | 19.0 R☉ |
| Luminosity | 229 L☉ |
| Temperature | 4,600 K |
| Metallicity [Fe/H] | +0.08 dex |
| Rotational velocity (v sin i) | 14.5 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
7 Boötis is a single[5] star in the northern constellation of Boötes,[4] located 590 light-years away from the Sun.[1] It is barely visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of 5.71.[2] 7 Boötis is moving closer to the Earth with a heliocentric radial velocity of −11 km/s.[1]
This is an evolved giant star with a stellar classification of G5 III, currently at the end of the Hertzsprung gap. It has a weak level of magnetic activity but a fairly strong X-ray luminosity of 3.72×1020 erg s−1. The rotation rate is moderate, with a projected rotational velocity of 14.5 km/s. It has four times the mass of the Sun and has expanded to 19 times the Sun's radius. The star is radiating 229 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,600 K.[2]
References
[edit]- ^ a b c d e f g h 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.
- ^ a b c d e f Aurière, M.; et al. (February 2015), "The magnetic fields at the surface of active single G-K giants", Astronomy & Astrophysics, 574: 30, arXiv:1411.6230, Bibcode:2015A&A...574A..90A, doi:10.1051/0004-6361/201424579, S2CID 118504829, A90.
- ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015, S2CID 119257644.
- ^ a b "7 Boo". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved September 13, 2018.
- ^ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
