Astronomy:7 Piscium

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Short description: Star in the constellation Pisces
7 Piscium
Observation data
Equinox J2000.0]] (ICRS)
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
Distance343 ± 7 ly
(105 ± 2 pc)
Absolute magnitude (MV)−0.56[5]
Details[6]
Mass1.37[7] M
Radius22.06+1.38
−3.16
[1] R
Luminosity163±4[1] L
Surface gravity (log g)1.81±0.28 cgs
Temperature4,314±80 K
Metallicity [Fe/H]−0.71±0.12 dex
Age4.58[7] Gyr
Other designations
b Piscium, 7 Psc, BD+04°4997, FK5 3871, HD 220009, HIP 115227, HR 8878, SAO 128126[8]
Database references
SIMBADdata

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

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 Høg, E. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode2000A&A...355L..27H. 
  3. 3.0 3.1 Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey 5. Bibcode1999MSS...C05....0H. 
  4. Johnson, H. L. (1966). "UBVRIJKL Photometry of the Bright Stars". Communications of the Lunar and Planetary Laboratory 4: 99. Bibcode1966CoLPL...4...99J. 
  5. 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  6. 6.0 6.1 Prugniel, Ph. et al. (July 2011), "The atmospheric parameters and spectral interpolator for the MILES stars", Astronomy & Astrophysics 531: A165, doi:10.1051/0004-6361/201116769, Bibcode2011A&A...531A.165P. 
  7. 7.0 7.1 7.2 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, Bibcode2015AJ....150...88L. 
  8. 8.0 8.1 "7 Psc". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=7+Psc. 
  9. 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  10. 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, doi:10.1051/0004-6361:20065867, Bibcode2007A&A...468..679S 
  11. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode2000ApJ...539..732A.