7 Piscium
7 Piscium is a single[9] star in the zodiac constellation of Pisces,[8] located around 343 light years away from the Sun.[1] It has the Bayer designation b Piscium; 7 Piscium is the Flamsteed designation. This object is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 5.07.[2] It is moving further from the Earth with a heliocentric radial velocity of 40 km/s.[1]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Pisces |
| Right ascension | 23h 20m 20.58306s[1] |
| Declination | +05° 22′ 52.7000″[1] |
| Apparent magnitude (V) | 5.069[2] |
| Characteristics | |
| Spectral type | K1 IV[3] |
| U−B color index | +1.12[4] |
| B−V color index | +1.204±0.002[5] |
| Astrometry | |
| Radial velocity (Rv) | 40.46±0.18[1] km/s |
| Proper motion (μ) | RA: 78.829[1] mas/yr Dec.: −59.228[1] mas/yr |
| Parallax (π) | 9.5042 ± 0.1880[1] mas |
| Distance | 343 ± 7 ly (105 ± 2 pc) |
| Absolute magnitude (MV) | −0.56[5] |
| Details[6] | |
| Mass | 1.37[7] M☉ |
| Radius | 22.06+1.38 −3.16[1] R☉ |
| Luminosity | 163±4[1] L☉ |
| Surface gravity (log g) | 1.81±0.28 cgs |
| Temperature | 4,314±80 K |
| Metallicity [Fe/H] | −0.71±0.12 dex |
| Age | 4.58[7] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a metal-deficient giant star[10] with a stellar classification of K1 IV.[3] It is a red clump giant, which indicates it is on the horizontal branch and is generating energy through the fusion of helium at its core.[11] The star is 4.58 billion years old with 1.37 times the mass of the Sun.[7] It has 22[1] times the Sun's radius and is radiating 163[1] times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,314 K.[6]
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.
- Høg, E.; et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27–L30. Bibcode:2000A&A...355L..27H.
- Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey. 5. Bibcode:1999MSS...C05....0H.
- Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory. 4: 99. Bibcode:1966CoLPL...4...99J.
- 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.
- Prugniel, Ph.; et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics, 531: A165, arXiv:1104.4952, Bibcode:2011A&A...531A.165P, doi:10.1051/0004-6361/201116769.
- Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal, 150 (3): 88, arXiv:1507.01466, Bibcode:2015AJ....150...88L, doi:10.1088/0004-6256/150/3/88.
- "7 Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-25.
- Eggleton, P. P.; Tokovinin, A. A. (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.
- Smiljanic, R.; Porto de Mello, G. F.; da Silva, L. (June 2007), "Abundance analysis of barium and mild barium stars", Astronomy & Astrophysics, 468 (2): 679–693, arXiv:astro-ph/0702421, Bibcode:2007A&A...468..679S, doi:10.1051/0004-6361:20065867
- Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278.