Rho Puppis

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Rho Puppis
Diagram showing star positions and boundaries of the Puppis constellation and its surroundings
Cercle rouge 100%.svg

Location of ρ Puppis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Puppis
Right ascension 08h 07m 32.64882s[1]
Declination −24° 18′ 15.5679″[1]
Apparent magnitude (V) 2.78[2]
Spectral type F2mF5IIp[3]
U−B color index +0.17[2]
B−V color index +0.40[2]
Variable type δ Sct[4]
Radial velocity (Rv) +46.1[5] km/s
Proper motion (μ) RA: –83.35[1] mas/yr
Dec.: +46.23[1] mas/yr
Parallax (π) 51.33 ± 0.15[1] mas
Distance 63.5 ± 0.2 ly
(19.48 ± 0.06 pc)
Mass 1.85[6] M
Radius 3.41[3] R
Luminosity 22[6] L
Surface gravity (log g) 3.70[7] cgs
Temperature 6,920[8] K
Metallicity [Fe/H] 0.35[7] dex
Rotational velocity (v sin i) 15[9] km/s
Age 2[10] Gyr
Other designations
ρ Puppis, ρ Pup, Rho Pup, 15 Puppis, CPD−23  3368, FK5 308, HD 67523, HIP 39757, HR 3185, SAO 175217.[11]

Rho Puppis (ρ Puppis, abbreviated Rho Pup, ρ Pup), also named Tureis,[12] is a star in the southern constellation of Puppis. With an average apparent visual magnitude of 2.78,[2] it is the third-brightest member of this generally faint constellation. Based upon parallax measurements made during the Hipparcos mission, Rho Puppis is located at a distance of 63.5 light-years (19.5 parsecs) from the Sun.[1]


ρ Puppis (Latinised to Rho Puppis) is the star's Bayer designation.

It bore the traditional name Tureis or Turais, which was shared by Iota Carinae.[13] In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN)[14] to catalogue and standardize proper names for stars. The WGSN approved the name Tureis for this star on 12 September 2016 and it is now so entered in the IAU Catalog of Star Names (Iota Carinae was given the name Aspidiske on 20 July 2016).[12]


At present Rho Puppis is moving away from the Sun with a radial velocity of +46.1 km s−1. The closest approach occurred about 394,000 years ago when it came within roughly 11.6 ly (3.6 pc) of the Solar System; about the same distance as Procyon in the present era.[15]

The variability of this star was announced in 1956 by American astronomer Olin J. Eggen.[4] It was determined to be a Delta Scuti-type variable star, making it one of the first stars of that type to be identified. Photometric observations dating back to 1946 provide a lengthy record of its pattern of pulsation; it undergoes periodic pulsations with a single period of 0.14088143(3) days,[16] or 7.1 cycles per day. During each cycle, the star's magnitude varies with an amplitude of 0.15 and the radial velocity varies by 10 km s−1. The peak brightness occurs 28.8 minutes following the minimum radial velocity.[4] The outer atmosphere's effective temperature of 6,920 K[8] is one of the lowest known for a Delta Scuti variable.[4]

Rho Puppis has an estimated age of about 2 billion years[10] and it has 3.4[3] times the Sun's radius. It has a stellar classification of F2mF5IIp,[3] which matches the spectrum of an F-type bright giant star. It shows stronger than normal absorption lines of metals—a term astronomers use for any element other than hydrogen and helium. The 'p' suffix indicates chemical peculiarities that mark it as a cooler temperature Am star.[17] Most such stars are found in binary star systems,[18] but this appears to be an exception as no companion has been discovered.[10][19] Evolved stars that show this combination of Delta Scuti variability with Am-like peculiarities of abundance have come to be known as ρ Pup stars.[20] The star's metallicity is more than double that in the Sun.[7]

This star shows an excess emission of infrared radiation, suggesting that there is a circumstellar disk of dust orbiting this star. The mean temperature of the emission is 85 K, corresponding to an orbital separation from the host star of 50 AU.[3][10]


  1. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752free to read, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357 
  2. ^ a b c d Bookmeyer, B. B.; et al. (August 1977), "Photoelectric UBV observations of RR Lyrae variable stars. Second list", Revista Mexicana de Astronomia y Astrofisica, 2: 235–258, Bibcode:1977RMxAA...2..235B 
  3. ^ a b c d e Rhee, Joseph H.; et al. (May 2007), "Characterization of Dusty Debris Disks: The IRAS and Hipparcos Catalogs", The Astrophysical Journal, 660 (2): 1556–1571, arXiv:astro-ph/0609555free to read, Bibcode:2007ApJ...660.1556R, doi:10.1086/509912 
  4. ^ a b c d Mathias, P.; et al. (November 1997), "A spectroscopic study of the delta Scuti star rho Puppis", Astronomy and Astrophysics, 327: 1077–1086, Bibcode:1997A&A...327.1077M 
  5. ^ Evans, D. S. (June 20–24, 1966), "The Revision of the General Catalogue of Radial Velocities", in Batten, Alan Henry; Heard, John Frederick, Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E 
  6. ^ a b Kaler, James B. (September 5, 2008), "TUREIS (Rho Puppis)", Stars, University of Illinois, retrieved 2012-02-25 
  7. ^ a b c Burkhart, C.; Coupry, M. F. (September 1991), "The A and Am-Fm stars. I - The abundances of Li, Al, Si, and Fe", Astronomy and Astrophysics, 249 (1): 205–216, Bibcode:1991A&A...249..205B 
  8. ^ a b Burkhart, C.; et al. (January 2005), "The field Am and ρ Puppis-like stars: Lithium and heavier elements", Astronomy and Astrophysics, 429: 1043–1049, Bibcode:2005A&A...429.1043B, doi:10.1051/0004-6361:20040467 
  9. ^ Bernacca, P. L.; Perinotto, M. (1970). "A catalogue of stellar rotational velocities". Contributi Osservatorio Astronomico di Padova in Asiago. 239 (1). Bibcode:1970CoAsi.239....1B. 
  10. ^ a b c d Rodriguez, David R.; Zuckerman, B. (February 2012), "Binaries among Debris Disk Stars", The Astrophysical Journal, 745 (2): 147, arXiv:1111.5618free to read, Bibcode:2012ApJ...745..147R, doi:10.1088/0004-637X/745/2/147 
  11. ^ "rho Pup -- Variable Star of delta Sct type", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-01-25 
  12. ^ a b "IAU Catalog of Star Names". Retrieved 28 July 2016. 
  13. ^ Moore, Patrick (2005), The observer's year: 366 nights of the universe, Practical Astronomy (2nd ed.), Springer, p. 346, ISBN 1-85233-884-9 
  14. ^ IAU Working Group on Star Names (WGSN), International Astronomical Union, retrieved 22 May 2016. 
  15. ^ García-Sánchez, J.; et al. (November 2001), "Stellar encounters with the solar system", Astronomy and Astrophysics, 379: 634–659, Bibcode:2001A&A...379..634G, doi:10.1051/0004-6361:20011330 
  16. ^ Moon, T.; van Antwerpen, C. (June 2009), "Period Changes in δ Scuti Stars: ρ Puppis", The Journal of the American Association of Variable Star Observers, 37 (1): 3–14, Bibcode:2009JAVSO..37....3M 
  17. ^ McGahee, Courtney; Gray, R. O. (January 2010), "Chemical Abundance Analysis of Rho Puppis Stars", Bulletin of the American Astronomical Society, 42: 339, Bibcode:2010AAS...21542520M 
  18. ^ Netopil, M.; et al. (November 2008), "Chemically peculiar stars and their temperature calibration", Astronomy and Astrophysics, 491 (2): 545–554, arXiv:0809.5131free to read, Bibcode:2008A&A...491..545N, doi:10.1051/0004-6361:200810325 
  19. ^ 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:0806.2878free to read. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x. 
  20. ^ Kochukhov, O. (March 2009), "Asteroseismology of chemically peculiar stars", Communications in Asteroseismology, 159: 61–70, arXiv:0812.0374free to read, Bibcode:2009CoAst.159...61K, doi:10.1553/cia159s61