Location of σ Puppis (circled) | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Puppis |
| Right ascension | 07 29 13.83263 |
| Declination | −43° 18′ 05.1674″ |
| Apparent magnitude (V) | 3.25 |
| Characteristics | |
| Spectral type | K5 III |
| U−B color index | +1.77 |
| B−V color index | +1.52 |
| Astrometry | |
| Radial velocity (Rv) | +87.3 km/s |
| Proper motion (μ) | RA: +199.39 mas/yr Dec.: −61.828 mas/yr |
| Parallax (π) | 17.0234 ± 0.5614 mas |
| Distance | 192 ± 6 ly (59 ± 2 pc) |
| Absolute magnitude (MV) | −0.50 |
| Orbit | |
| Period (P) | 257.8 days |
| Eccentricity (e) | 0.17 |
| Periastron epoch (T) | 20418.6 |
| Argument of periastron (ω) (secondary) | 349.3° |
| Semi-amplitude (K1) (primary) | 18.6 km/s |
| Details | |
| σ Pup A | |
| Mass | 1.65 M☉ |
| Radius | 43.7 R☉ |
| Luminosity | 344 L☉ |
| Surface gravity (log g) | 1.51 cgs |
| Temperature | 4,077±4 K |
| Rotational velocity (v sin i) | 3.0 km/s |
| Other designations | |
| σ Pup, Sigma Pup, CPD−43 1499, FK5 1194, GC 10040, HD 59717, HIP 36377, HR 2878, SAO 218755, WDS J07292-4318A | |
| Database references | |
| SIMBAD | data |
Sigma Puppis, Latinized from σ Puppis, is a binary star system in the southern constellation Puppis. It has an apparent visual magnitude of 3.25, which is bright enough to be visible to the naked eye at night from the Southern Hemisphere. Through a telescope, it appears as a bright, orange-hued star with a nearby white companion. Parallax measurements indicate this star is located at a distance of about 192 light-years (59 parsecs) from Earth.
This is a spectroscopic binary system, consisting of an orbiting pair of stars that have not been individually resolved with a telescope. Their orbital period is 257.8 days and the eccentricity is 0.17. The pair form an eclipsing binary of the Beta Lyrae type and a period of 130.5 days, or one half of their orbital period. The eclipse of the primary component causes a decline of 0.04 of a magnitude, while the secondary eclipse reduces the magnitude by 0.03.
The combined stellar classification is K5 III, which matches the spectrum of a giant star. The primary is 44 times larger than the Sun and 340 times more luminous. Its surface has an effective temperature of 4,077 K, giving it the orange hue of a K-type star. It shows the behavior of a slow irregular variable.
In addition to its binary components, Sigma Puppis has a more distant companion that has a matching proper motion, suggesting that it may be gravitationally bound to the binary. This magnitude 8.5 star is at an angular separation of 22.4 arcseconds with a position angle of 74° from Sigma Puppis, which is equivalent to a projected separation of 1,200 AU. In 1970, American astronomer Olin J. Eggen suggested that Sigma Puppis belonged to a moving group of stars that share a similar motion through space, and thereby a common origin. It served as the eponym for this, the σ Puppis group. The existence of this group was later brought into question.
References
- ^ Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ 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
- ^ Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, Ann Arbor: Dept. of Astronomy, University of Michigan: distributed by University Microfilms International, Bibcode:1978mcts.book.....H
- ^ Wood, Brian E.; Müller, Hans-Reinhard; Harper, Graham M. (2016-09-23), "Hubble Space Telescope Constraints on the Winds and Astrospheres of Red Giant Stars", The Astrophysical Journal, 829 (2): 74, arXiv:1607.07732, Bibcode:2016ApJ...829...74W, doi:10.3847/0004-637X/829/2/74, ISSN 0004-637X
- 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.
- ^ Batten, A. H.; Fletcher, J. M.; Mann, P. J. (1978), "Seventh catalogue of the orbital elements of spectroscopic binary systems", Publications of the Dominion Astrophysical Observatory Victoria, 15: 121–295, 150–151, Bibcode:1978PDAO...15..121B
- ^ Ayres, Thomas (2023-05-01). "In the Trenches of the Solar-Stellar Connection. VII. Wilson-Bappu 2022". The Astrophysical Journal Supplement Series. 266 (1): 6. Bibcode:2023ApJS..266....6A. doi:10.3847/1538-4365/acb535. ISSN 0067-0049. Sigma Puppis' database entry at VizieR.
- Costa, J. M.; et al. (February 2002), "The tidal effects on the lithium abundance of binary systems with giant component", Astronomy and Astrophysics, 382 (3): 1016–1020, arXiv:astro-ph/0111539, Bibcode:2002A&A...382.1016C, doi:10.1051/0004-6361:20011676, S2CID 17024265
- ^ "sig Pup -- Spectroscopic binary", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2010-01-05
- ^ Plotner, Tammy; Mann, Terry (2007), The Night Sky Companion: A Yearly Guide to Sky-Watching, Patrick Moore's Practical Astronomy Series, Springer, p. 156, ISBN 978-0-387-71608-4, retrieved 2012-01-11
- ^ Otero, Sebastián A. (October 2007), "New Elements for 54 Eclipsing Binaries", Open European Journal on Variable Stars, 72 (1): 1–19, Bibcode:2007OEJV...72....1O
- ^ Samus, N. N.; Durlevich, O. V. (February 12, 2009), GCVS Variability Types and Distribution Statistics of Designated Variable Stars According to their Types of Variability, Sternberg Astronomical Institute, Moscow University, retrieved 2012-04-18
- "The Colour of Stars". Australia National Telescope Facility. Retrieved 2024-05-27.
- Burnham, Robert (1978), Burnham's celestial handbook: an observer's guide to the universe beyond the solar system, Dover books explaining science, vol. 3 (2nd ed.), Courier Dover Publications, p. 150, ISBN 0-486-23673-0, retrieved 2012-01-11
- Eggen, O. J. (June 1971), "The ζ Herculis, σ Puppis, ∈ Indi, and η Cephei Groups of Old Disk Population Stars", Publications of the Astronomical Society of the Pacific, 83 (493): 251, Bibcode:1971PASP...83..251E, doi:10.1086/129119
- Taylor, B. J. (October 2000), "A statistical analysis of the metallicities of nine old superclusters and moving groups", Astronomy and Astrophysics, 362: 563–579, Bibcode:2000A&A...362..563T
