7 Piscium

7 Piscium
Observation data; Epoch J2000.0 Equinox J2000.0
Constellation	Pisces
Right ascension	23h 20m 20.58306s
Declination	+05° 22′ 52.7000″
Apparent magnitude (V)	5.069
Characteristics
Spectral type	K1 IV
U−B color index	+1.12
B−V color index	+1.204±0.002
Astrometry
Radial velocity (Rv)	40.46±0.18 km/s
Proper motion (μ)	RA: 78.829 mas/yr ; Dec.: −59.228 mas/yr
Parallax (π)	9.5042 ± 0.1880 mas
Distance	343 ± 7 ly ; (105 ± 2 pc)
Absolute magnitude (MV)	−0.56
Details
Mass	1.37 M☉
Radius	22.06+1.38; −3.16 R☉
Luminosity	163±4 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 Gyr
Other designations
	b Piscium, 7 Psc, BD+04°4997, FK5 3871, HD 220009, HIP 115227, HR 8878, SAO 128126
Database references
SIMBAD	data

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]

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

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k ^l 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.
^ ^a ^b 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.
^ ^a ^b 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.
^ ^a ^b 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 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, S2CID 54940439.
^ ^a ^b ^c 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, S2CID 118505114.
^ ^a ^b "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, S2CID 14878976.
^ 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, S2CID 5863942
^ 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, S2CID 16673121.