Psi2 Piscium

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Psi2 Piscium
Pisces IAU.svg
Red circle.svg

Location of ψ2 Piscium (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Pisces
Right ascension 01h 07m 57.16387s[1]
Declination +20° 44′ 20.8310″[1]
Apparent magnitude (V) +5.56[2]
Spectral type A3 V[3]
B−V color index +0.12[2]
Radial velocity (Rv) −15.2±0.9[4] km/s
Proper motion (μ) RA: +86.72[1] mas/yr
Dec.: −82.75[1] mas/yr
Parallax (π) 21.14 ± 0.77[1] mas
Distance 154 ± 6 ly
(47 ± 2 pc)
Absolute magnitude (MV) +2.19[5]
Mass 1.82[6] M
Radius 2.0[7] R
Luminosity 13[3] L
Surface gravity (log g) 4.36±0.14[6] cgs
Temperature 8,611±293[6] K
Rotational velocity (v sin i) 149[3] km/s
Age 250[6] Myr
Other designations
ψ3 Psc, 79 Piscium, BD+19° 185, HD 6695, HIP 5310, HR 328, SAO 74506[8]
Database references

Psi2 Piscium (ψ2 Piscium) is a white-hued star in the zodiac constellation of Pisces. It is faintly visible to the naked eye, having an apparent visual magnitude of +5.56.[2] Based upon an annual parallax shift of 8.66 mas as seen from Earth,[1] it is located about 380 light years from the Sun. It has a peculiar velocity of 14.6±2.9 km/s, indicating it is a runaway star.[9]

This is a suspected binary star system,[10] with a companion star at an angular separation of 0.357±0.002 arc seconds along a position angle of 174.99°±0.30° from the primary, as of 2008. This corresponds to a projected separation of 16.88±0.62 AU.[11] The brighter component is an A-type main sequence star with a stellar classification of A3 V.[3] The system is a source of X-ray emission with a luminosity of 143.9×1020 W, which is most likely originating from the cooler companion since A-type main sequence stars are not expected to be magnetically active.[12]


  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752Freely accessible, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c Høg, E.; et al. (March 2000), "The Tycho-2 catalogue of the 2.5 million brightest stars", Astronomy and Astrophysics, 355: L27−L30, Bibcode:2000A&A...355L..27H. 
  3. ^ a b c d Zorec, J.; Royer, F. (January 2012), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy & Astrophysics, 537: A120, Bibcode:2012A&A...537A.120Z, arXiv:1201.2052Freely accessible, doi:10.1051/0004-6361/201117691. 
  4. ^ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, Bibcode:2012A&A...546A..61D, arXiv:1208.3048Freely accessible, doi:10.1051/0004-6361/201219219, A61. 
  5. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, Bibcode:2012AstL...38..331A, arXiv:1108.4971Freely accessible, doi:10.1134/S1063773712050015. 
  6. ^ a b c d David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, Bibcode:2015ApJ...804..146D, arXiv:1501.03154Freely accessible, doi:10.1088/0004-637X/804/2/146. 
  7. ^ Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (Third ed.), 367: 521–524, Bibcode:2001A&A...367..521P, arXiv:astro-ph/0012289Freely accessible, doi:10.1051/0004-6361:20000451. 
  8. ^ "psi02 Psc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-23. 
  9. ^ Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, Bibcode:2011MNRAS.410..190T, arXiv:1007.4883Freely accessible, doi:10.1111/j.1365-2966.2010.17434.x. 
  10. ^ 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, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878Freely accessible, doi:10.1111/j.1365-2966.2008.13596.x. 
  11. ^ De Rosa, R. J.; et al. (2012), "The Volume-limited A-Star (VAST) survey - II. Orbital motion monitoring of A-type star multiples", Monthly Notices of the Royal Astronomical Society, 422 (4): 2765, Bibcode:2012MNRAS.422.2765D, arXiv:1112.3666Freely accessible, doi:10.1111/j.1365-2966.2011.20397.x. 
  12. ^ Schröder, C.; Schmitt, J. H. M. M. (November 2007), "X-ray emission from A-type stars", Astronomy and Astrophysics, 475 (2): 677−684, Bibcode:2007A&A...475..677S, doi:10.1051/0004-6361:20077429.