Astronomy:Pi Coronae Borealis
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Corona Borealis |
| Right ascension | 15h 43m 59.29973s[1] |
| Declination | +32° 30′ 56.9047″[1] |
| Apparent magnitude (V) | 5.578[2] |
| Characteristics | |
| Spectral type | G9 III:[2] |
| B−V color index | 1.074[3] |
| Astrometry | |
| Radial velocity (Rv) | −4.94±0.51[3] km/s |
| Proper motion (μ) | RA: −29.92[1] mas/yr Dec.: −8.85[1] mas/yr |
| Parallax (π) | 13.40 ± 0.21[1] mas |
| Distance | 243 ± 4 ly (75 ± 1 pc) |
| Absolute magnitude (MV) | +1.21[4] |
| Details[3] | |
| Mass | 1.61[2] M☉ |
| Radius | 10 R☉ |
| Luminosity | 39 L☉ |
| Surface gravity (log g) | 2.7 cgs |
| Temperature | 4,667±5 K |
| Metallicity [Fe/H] | −0.15 dex |
| Rotational velocity (v sin i) | 3.5 km/s |
| Age | 4.6[2] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Pi Coronae Borealis, Latinized from π Coronae Borealis, is a solitary,[6] orange-hued star in the northern constellation of Corona Borealis. Its apparent magnitude is 5.58,[2] which is bright enough to be faintly visible to the naked eye. Based upon an annual parallax shift of 13.40 mas as measured from Earth, it is located about 243 light years from the Sun. The star is moving closer to the Sun with a radial velocity of −5 km/s.[3] It is most likely (98% chance) a member of the thin disk population.[7]
This is an evolved G-type giant star with a stellar classification of G9 III:, where the ':' indicates some uncertainty about the classification. (Bartkevicius and Lazauskaite (1997) classify it as K0 III.)[8] The star has 1.61[2] times the mass of the Sun and has expanded to about 10 times the Sun's radius. The abundance of iron is lower than in the Sun: the star is considered metal deficient.[8] It is around 4.6[2] billion years old and is radiating 39 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,667 K.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ 3.0 3.1 3.2 3.3 3.4 Massarotti, Alessandro et al. (January 2008), "Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity", The Astronomical Journal 135 (1): 209–231, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ "pi. CrB". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=pi.+CrB.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Soubiran, C. et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics 480 (1): 91–101, doi:10.1051/0004-6361:20078788, Bibcode: 2008A&A...480...91S.
- ↑ 8.0 8.1 Bartkevicius, A.; Lazauskaite, R. (December 1997), "Classification of Population II Stars in the Vilnius Photometric System. II. Results", Baltic Astronomy 6 (4): 499–572, doi:10.1515/astro-1997-0402, Bibcode: 1997BaltA...6..499B.
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