Psi2 Piscium

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

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
Distance154 ± 6 ly
(47 ± 2 pc)
Absolute magnitude (MV)+2.19[5]
Mass1.82[6] M
Radius2.0[7] R
Luminosity13[3] L
Surface gravity (log g)4.36±0.14[6] cgs
Temperature8,611±293[6] K
Rotational velocity (v sin i)149[3] km/s
Age250[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, arXiv:0708.1752, Bibcode:2007A&A...474..653V, 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, doi:10.1888/0333750888/2862.
  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, arXiv:1201.2052, Bibcode:2012A&A...537A.120Z, 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, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  5. ^ 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.
  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, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, 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, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, 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, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, 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, arXiv:1112.3666, Bibcode:2012MNRAS.422.2765D, 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.