Astronomy:KQ Puppis

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Short description: Binary star in the constellation Puppis
KQ Puppis
M47 tel114.png
KQ Puppis is the bright red star on the right, with M47 on the left.
Observation data
Equinox J2000.0]] (ICRS)
Constellation Puppis
Right ascension  07h 33m 47.96383s[1]
Declination −14° 31′ 26.0026″[1]
Apparent magnitude (V) +4.97[2] (4.82 - 5.17[3])
Characteristics
Spectral type M2Iab + B0Ve[4]
U−B color index +0.29[2]
B−V color index +1.41[2]
Variable type LC[3]
Astrometry
Radial velocity (Rv)+22[5] km/s
Proper motion (μ) RA: -6.584[6] mas/yr
Dec.: +3.34[6] mas/yr
Parallax (π)1.4894 ± 0.2296[6] mas
Distanceapprox. 2,200 ly
(approx. 700 pc)
Orbit[7]
Period (P)9,752 days
Eccentricity (e)0.46
Inclination (i)60-80°
Details
Cool primary
Mass13-20[7] M
Radius415[8] R
Luminosity26,500 - 28,100[8] L
Temperature3,662[9][8] K
Hot secondary
Mass17[7] M
Radius4.35[7] R
Luminosity13,800[7] L
Temperature30,000[7] K
Other designations
KQ Pup, BD−14°1971, HIP 36773, HR 2902, NGC 2422 9, SAO 153072
Primary: HD 60414
Secondary: HD 60415
Database references
SIMBADdata

KQ Puppis (KQ Pup) is a spectroscopic binary variable star in the constellation Puppis. A red supergiant star and a hot main sequence star orbit each other every 9,742 days. Its apparent magnitude varies between 4.82 and 5.17.

The KQ Puppis system consists of a fairly typical M2 supergiant, in orbit with a hotter less luminous star. The hotter star is surrounded by a disc of material being transferred from the cool supergiant. This type of binary is referred to a VV Cephei system, although in this case there are no eclipses of either star.[7] A portion of the disc does appear to be eclipsed and this is detected as a strong drop in far-ultraviolet radiation for about a third of the orbit.[4]

A light curve for KQ Puppis, plotted from Hipparcos data[10]

The red supergiant primary star has been compared to Betelgeuse.[7] It shows small amplitude irregular pulsations, and also some variation associated with the orbital motion.[11] The nature of the secondary is less certain. The spectrum shows high excitation features that would indicate an early B or hotter spectral type, but these may be associated with the disc rather than that star itself. Other studies have found a spectrum similar to an A supergiant, but this is thought to be an artefact of a B-type shell star.[12]

KQ Puppis has been catalogued as an outlying member of the open cluster Messier 47 (NGC 2422) and would be the brightest member of that cluster.[13] Membership is uncertain as it appears to be more distant than the other stars in the cluster.[14]

References

  1. 1.0 1.1 Van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 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: 0. Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 Samus, N. N. 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: 02025. Bibcode2009yCat....102025S. 
  4. 4.0 4.1 González-Riestra, R.; Rossi, C.; Viotti, R. F. (2003). "First far-UV observations of KQ Puppis with FUSE". Astronomy and Astrophysics 399 (2): 681. doi:10.1051/0004-6361:20021830. Bibcode2003A&A...399..681G. 
  5. Wilson, Ralph Elmer (1953). "General catalogue of stellar radial velocities". Washington: 0. Bibcode1953GCRV..C......0W. 
  6. 6.0 6.1 6.2 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 Rossi, C.; Altamore, A.; Baratta, G. B.; Friedjung, M.; Viotti, R. (1992). "The spectrum of the VV Cephei star KQ Puppis (Boss 1985). III - A possible model". Astronomy and Astrophysics 256: 133. Bibcode1992A&A...256..133R. 
  8. 8.0 8.1 8.2 Messineo, M.; Brown, A. G. A. (2019). "A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2". The Astronomical Journal 158 (1): 20. doi:10.3847/1538-3881/ab1cbd. Bibcode2019AJ....158...20M. 
  9. McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society 427 (1): 343–357. doi:10.1111/j.1365-2966.2012.21873.x. Bibcode2012MNRAS.427..343M. 
  10. "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access. 
  11. Viotti, R.; Rossi, C.; Muratorio, G. (1998). "Optical and near-IR observations of variable stars with AURELIE". Astronomy and Astrophysics Supplement 128 (3): 447. doi:10.1051/aas:1998156. Bibcode1998A&AS..128..447V. 
  12. Parsons, Sidney B.; Ake, Thomas B. (1998). "Ultraviolet and Optical Studies of Binaries with Luminous Cool Primaries and Hot Companions. V. The Entire IUE Sample". The Astrophysical Journal Supplement Series 119 (1): 83. doi:10.1086/313152. Bibcode1998ApJS..119...83P. 
  13. Van Schewick, H. (1966). "Untersuchungen uber die Eigenbewegungen von Sternhaufen. XII. NGC 2422, NGC 2423, NGC 7209 und An. Bakhatova I im Sel. Area 40". Veroeff. Univ. Sternw. Bonn 74: 1. Bibcode1966VeBon..74....1V. 
  14. Baumgardt, H.; Dettbarn, C.; Wielen, R. (2000). "Absolute proper motions of open clusters. I. Observational data". Astronomy and Astrophysics Supplement 146 (2): 251. doi:10.1051/aas:2000362. Bibcode2000A&AS..146..251B.