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Epsilon Pyxidis

Location of ε Pyxidis (circled)
Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Pyxis
Right ascension	09 09 56.41024
Declination	−30° 21′ 55.4460″
Apparent magnitude (V)	+5.60
Characteristics
Spectral type	A4 IV
U−B color index	+0.16
B−V color index	+0.16
Astrometry
Radial velocity (Rv)	−9.7±0.3 km/s
Proper motion (μ)	RA: −1.93 mas/yr Dec.: −48.99 mas/yr
Parallax (π)	15.39 ± 0.30 mas
Distance	212 ± 4 ly (65 ± 1 pc)
Absolute magnitude (MV)	+2.00
Details
ε Pyx A
Mass	2.07 M☉
Luminosity	19 L☉
Surface gravity (log g)	3.26 cgs
Temperature	6368±1806 K
Metallicity	+0.04 dex
Rotational velocity (v sin i)	108.3±0.3 km/s
Age	560 Myr
Other designations
ε Pyx, CPD−29° 2933, FK5 1241, HD 78922, HIP 45001, HR 3644, SAO 200047, WDS J09099-3022A
Database references
SIMBAD	data

Epsilon Pyxidis (ε Pyxidis) is quadruple star system in the southern constellation of Pyxis. It is faintly visible to the naked eye, having a combined apparent visual magnitude of +5.60. Based upon an annual parallax shift of 15.39 mas as seen from Earth, it is located around 212 light years from the Sun. The system is deemed to be a member of the Sirius supercluster of stars that share a common motion through space.

The primary, component A, is a white-hued A-type subgiant star with a stellar classification of A4 IV. It is a microvariable, showing a 0.0056 change in magnitude with a frequency of 0.16245 times per day. Epsilon Pyxidis has been catalogued as an Am star, although this remains uncertain. It has double the mass of the Sun and radiates 19 times the Sun's luminosity from its photosphere at an effective temperature of 6,368 K.

In addition to a close companion of unknown type at an angular separation of 0.17 arc seconds, the primary shares an orbit with a binary star system, components B and C, that lie at an angular separation of 17.8 arc seconds. At the estimated distance of this system, this corresponds to a projected separation of around 1,150 AU. The B/C pair consist of visual magnitude 10.5 and 10.8 stars with a mean separation of 0.3 arc seconds. They have estimated mass of 90% and 95% that of the Sun, respectively.

References

1. ^ 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, S2CID 18759600.
2. ^ Mendoza, E. E.; et al. (June 1978), "UBVRI photometry of 225 AM stars", Astronomical Journal, 83: 606–614, Bibcode:1978AJ.....83..606M, doi:10.1086/112242.
3. ^ Houk, Nancy (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 3, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1982mcts.book.....H.
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, S2CID 59451347, A61.
5. ^ Eggen, Olin J. (August 1998), "The Sirius Supercluster and Missing Mass near the Sun", The Astronomical Journal, 116 (2): 782–788, Bibcode:1998AJ....116..782E, doi:10.1086/300465.
6. ^ De Rosa, R. J.; et al. (2013), "The VAST Survey – III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216, arXiv:1311.7141, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932.
7. ^ McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x, S2CID 118665352.
8. ^ Casagrande, L.; et al. (2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy & Astrophysics, 530 (A138): 21, arXiv:1103.4651, Bibcode:2011A&A...530A.138C, doi:10.1051/0004-6361/201016276, S2CID 56118016.
9. Díaz, C. G.; et al. (July 2011), "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum", Astronomy & Astrophysics, 531: A143, arXiv:1012.4858, Bibcode:2011A&A...531A.143D, doi:10.1051/0004-6361/201016386, S2CID 119286673.
10. "eps Pyx". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-07-18.{{cite web}}: CS1 maint: postscript (link)
11. ^ 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, S2CID 14878976.
12. 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.
13. Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics, 498 (3): 961–966, Bibcode:2009A&A...498..961R, doi:10.1051/0004-6361/200810788.

v t e Constellation of Pyxis
List of stars in Pyxis Pyxis in Chinese astronomy
Stars	Bayer α β γ δ ε ζ η θ κ λ Variable T RZ TY UZ VW VY WX XX AK CS HR 3384 3430 3597 HD 73267 77338 Other Gliese 317 Gliese 318
Exoplanets Gliese 317 b HD 73256 b HD 73267 b
Star clusters NGC 2627 Pyxis globular cluster
Nebulae K 1-2 NGC 2818
Galaxies	NGC 2613 2663 Other Hen 2-10
Category

• A-type subgiants
• Multiple star systems
• Bayer objects
• Pyxis
• Durchmusterung objects
• Henry Draper Catalogue objects
• Hipparcos objects
• Bright Star Catalogue objects