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R Puppis

Not to be confused with Rho Puppis.
R Puppis
Location of R Puppis (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Puppis
Right ascension 07h 40m 52.597s[1]
Declination −31° 39′ 40.20″[1]
Apparent magnitude (V) 6.50 - 6.71[2]
Characteristics
Spectral type G2 0-Ia[3]
U−B color index +0.85[4]
B−V color index +1.18[4]
Variable type SRd[2]
Astrometry
Radial velocity (Rv)+68.22[1] km/s
Proper motion (μ) RA: −2.251[1] mas/yr
Dec.: +3.222[1] mas/yr
Parallax (π)0.2440 ± 0.0180 mas[1]
Distance13,400 ± 1,000 ly
(4,100 ± 300 pc)
Absolute magnitude (MV)−7.8[5]
Details
Mass14.3[6] M☉
Radius477+28
−22[7] R☉
Luminosity96,600±26,100[7] L☉
Surface gravity (log g)0.30[8] cgs
Temperature5,495; (4,100±68 – 6,500)[8] K
Metallicity [Fe/H]−0.25[8] dex
Other designations
CD−31°4910, GSC 07106-03582, HIP 37415, HR 2974, HD 62058
Database references
SIMBADdata
NGC 2439, with R Puppis the brightest star

R Puppis is a variable star in the constellation Puppis. It is a rare yellow hypergiant and a candidate member of the open cluster NGC 2439. It is also an MK spectral standard for the class G2 0-Ia.[9]

Variability

A visual band light curve for R Puppis, plotted from ASAS data[10]

R Puppis was identified as a variable star in 1879, and described as having a range of over a magnitude.[11] Numerous observations over the following 100 years failed to confirm the variations, until the 1970s when clear brightness changes were observed.[12] These were confirmed by later observations, but with a total visual amplitude of only about 0.2 magnitudes.[11]

Variable stars such as R Puppis have been described as pseudo-Cepheids, because they lie above the high-luminosity portion of the instability strip and their variations are similar to those of Cepheids although less regular.[11] R Puppis is formally classified as a semiregular variable of type SRd, meaning F, G, or K giants or supergiants.[2]

References

  1. ^ a b c d e f 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.
  2. ^ a b c Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
  3. ^ Keenan, Philip C.; McNeil, Raymond C. (1989). "The Perkins catalog of revised MK types for the cooler stars". Astrophysical Journal Supplement Series. 71: 245. Bibcode:1989ApJS...71..245K. doi:10.1086/191373. S2CID 123149047.
  4. ^ a b Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237....0D.
  5. ^ Arellano Ferro, A.; Parrao, L. (1990). "Colour excesses and absolute magnitudes for non-Cepheid F-G supergiants from uvbybeta photometry". Astronomy and Astrophysics. 239: 205. Bibcode:1990A&A...239..205A.
  6. ^ Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. (2022). "VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022)". Vizier Online Data Catalog. Bibcode:2022yCat.1354....0A.
  7. ^ a b 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.
  8. ^ a b c Usenko, I. A.; Kniazev, A. Yu.; Berdnikov, L. N.; Kravtsov, V. V. (2011). "Spectroscopic studies of Cepheids (S Cru, AP Pup, AX Cir, S TrA, T Cru, R Mus, S Mus, U Car) and semiregular bright supergiants (V382 Car, HD 75276, R Pup) in the southern hemisphere". Astronomy Letters. 37 (7): 499. Bibcode:2011AstL...37..499U. doi:10.1134/S1063773711070061. S2CID 122968535.
  9. ^ Garcia, B. (1989). "A list of MK standard stars". Bulletin d'Information du Centre de Données Stellaires. 36: 27. Bibcode:1989BICDS..36...27G.
  10. ^ "ASAS All Star Catalogue". The All Sky Automated Survey. Retrieved 8 December 2021.
  11. ^ a b c Eggen, O. J. (March 1983). "Pseudocepheids. I. R Puppis, HR 4441, HR 4511, and AI CMi". Astronomical Journal. 88: 386–403. Bibcode:1983AJ.....88..386E. doi:10.1086/113323.
  12. ^ Stift, M. J. (September 1978). "R Pup - a Variable after all". Information Bulletin on Variable Stars. 1473: 1. Bibcode:1978IBVS.1473....1S.
Quelle: https://en.wikipedia.org/wiki/R_Puppis