Astronomy:QU Normae

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Short description: Star in the constellation Norma
QU Normae
Norma constellation map.svg
Red circle.svg
Location of QU Normae (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Norma
Right ascension  16h 29m 42.32668s[1]
Declination −46° 14′ 35.6022″[1]
Apparent magnitude (V) 5.37[2] (5.27 - 5.41[3])
Characteristics
Spectral type B1.5 Iap[4]
U−B color index −0.44[2]
B−V color index +0.62[2]
Variable type α Cyg[3]
Astrometry
Radial velocity (Rv)−14.80 ± 3.2[5] km/s
Proper motion (μ) RA: −4.54[1] mas/yr
Dec.: −1.51[1] mas/yr
Parallax (π)1.79 ± 0.70[1] mas
Distanceapprox. 1,800 ly
(approx. 600 pc)
Absolute magnitude (MV)−7.50[6]
Details
Mass43[7] M
Radius58[8] R
Luminosity417,000[6] L
Surface gravity (log g)2.00[7] cgs
Temperature17,000[7] K
Rotational velocity (v sin i)44[7] km/s
Other designations
QU Normae, HD 148379, HIP 80782, HR 6131, CD−45°10697
Database references
SIMBADdata

QU Normae, also known as HR 6131, is a blue supergiant star in the constellation Norma. It is also a variable star, thought to be an α Cyg variable.

The apparent magnitude of QU Normae varies somewhat irregularly between 5.27 and 5.41. The General Catalogue of Variable Stars quotes a period of 4.818 days,[3] but other research only shows likely periods longer than 10 days.[9]

A light curve for QU Normae, plotted from Hipparcos data[10]

QU Normae has a spectral type B1.5 Ia, a luminous supergiant that has swollen and cooled off the main sequence. Surface abundances suggest that it has not yet passed through a red supergiant phase.[6] Around 1,820 light-years distant, it shines with a luminosity approximately 417,000 times that of the Sun and has a diameter around 58 times that of the Sun.

References

  1. 1.0 1.1 1.2 1.3 1.4 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. Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 3.2 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. Bibcode2009yCat....102025S. 
  4. Chini, R.; Hoffmeister, V. H.; Nasseri, A.; Stahl, O.; Zinnecker, H. (2012). "A spectroscopic survey on the multiplicity of high-mass stars". Monthly Notices of the Royal Astronomical Society 424 (3): 1925. doi:10.1111/j.1365-2966.2012.21317.x. Bibcode2012MNRAS.424.1925C. 
  5. Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode2006AstL...32..759G. 
  6. 6.0 6.1 6.2 Lennon, D. J.; Dufton, P. L. (1986). "Evolutionary effects on the surface abundances of an early-type supergiant". Astronomy and Astrophysics 155: 79. Bibcode1986A&A...155...79L. 
  7. 7.0 7.1 7.2 7.3 Fraser, M.; Dufton, P. L.; Hunter, I.; Ryans, R. S. I. (2010). "Atmospheric parameters and rotational velocities for a sample of Galactic B-type supergiants". Monthly Notices of the Royal Astronomical Society 404 (3): 1306. doi:10.1111/j.1365-2966.2010.16392.x. Bibcode2010MNRAS.404.1306F. 
  8. Van Leeuwen, F.; Van Genderen, A. M.; Zegelaar, I. (1998). "Hipparcos photometry of 24 variable massive stars (α Cygni variables)". Astronomy and Astrophysics Supplement Series 128: 117–129. doi:10.1051/aas:1998129. Bibcode1998A&AS..128..117V. 
  9. "Hipparcos Tools Interactive Data Access". ESA. https://www.cosmos.esa.int/web/hipparcos/interactive-data-access.