Article · Wikipedia archive · Last revised Jun 26, 2026

Kappa Pyxidis

Kappa Pyxidis, Latinized from κ Pyxidis, is a single, orange-hued star in the southern constellation of Pyxis. It is visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.62. The star is located approximately 520 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −45 km/s and may come as close as 308 light-years in around 2.6 million years. It is moving through space at the rate of 53.7 km/s relative to the Sun and is following an orbit through the Milky Way galaxy with a large eccentricity of 0.68

Last revised
Jun 26, 2026
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κ Pyxidis
Location of κ Pyxidis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Pyxis
Right ascension 09h 08m 02.88015s1
Declination −25° 51′ 30.7331″1
Apparent magnitude (V) 4.622
Characteristics
Spectral type K4III3
U−B color index +1.874
B−V color index +1.594±0.0042
Astrometry
Radial velocity (Rv)−44.7±2.85 km/s
Proper motion (μ) RA: +34.7711 mas/yr
Dec.: +0.0091 mas/yr
Parallax (π)6.3116±0.2408 mas1
Distance520 ± 20 ly
(158 ± 6 pc)
Absolute magnitude (MV)−1.532
Details
Radius66.70+0.34
−2.341 R☉
Luminosity927±401 L☉
Surface gravity (log g)1.44±0.226 cgs
Temperature3,931±316 K
Metallicity [Fe/H]−0.22±0.086 dex
Other designations
κ Pyx, CPD−25°4067, GC 12614, HD 78541, HIP 44824, HR 3628, SAO 177002, PPM 255695, CCDM J09080-2552AB, WDS J09080-2552AB7
Database references
SIMBADdata

Kappa Pyxidis, Latinized from κ Pyxidis, is a single,8 orange-hued star in the southern constellation of Pyxis. It is visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.62.2 The star is located approximately 520 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −45 km/s5 and may come as close as 308 light-years in around 2.6 million years. It is moving through space at the rate of 53.7 km/s relative to the Sun and is following an orbit through the Milky Way galaxy with a large eccentricity of 0.682

This is an aging giant with a stellar classification of K4III,3 having exhausted the supply of hydrogen at its core then expanded and cooled. At present it has 671 times the radius of the Sun. It is a variable star of uncertain type, changing brightness with an amplitude of 0.0058 in visual magnitude over a period of 8.5 days.9 The star radiates 927 times the luminosity of the Sun from its bloated photosphere at an effective temperature of 3,931 K.6 A magnitude 10 visual companion is located at an angular separation of 2.1 arcseconds.10

References

References

  1. 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.
  2. 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.
  3. Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins Catalog of Revised MK Types for the Cooler Stars", The Astrophysical Journal Supplement Series, 71: 245, Bibcode:1989ApJS...71..245K, doi:10.1086/191373.
  4. Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J.
  5. 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, S2CID 59451347, A61.
  6. 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.
  7. "kap Pyx". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-09-14.
  8. 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  9. Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331 (1): 45–59, arXiv:astro-ph/0112194, Bibcode:2002MNRAS.331...45K, doi:10.1046/j.1365-8711.2002.05150.x, S2CID 10505995.
  10. Privett, Grant; Jones, Kevin (2013), The Constellation Observing Atlas, New York, New York: Springer Science & Business Media, p. 168, Bibcode:2013coa..book.....P, ISBN 9781461476481.