V424 Lacertae

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V424 Lacertae
Lacerta constellation map.svg
Red circle.svg

Location of V424 Lacertae (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Lacerta
Right ascension 22h 56m 25.99818s[1]
Declination +49° 44′ 00.7532″[1]
Apparent magnitude (V) +4.94[2]
Characteristics
Spectral type K5 Ib[3]
U−B color index +1.95[2]
B−V color index +1.77[2]
Variable type Lc[4]
Astrometry
Radial velocity (Rv) −9.50[5] km/s
Proper motion (μ) RA: −0.48 ± 0.18[1] mas/yr
Dec.: −3.43 ± 0.19[1] mas/yr
Parallax (π) 2.04 ± 0.26[1] mas
Distance 575[6] pc
Absolute magnitude (MV) −4.27[7]
Details
Mass 6.8[8] M
Radius 260[7] R
Luminosity 12,600[7] L
Surface gravity (log g) +0.50[8] cgs
Temperature 3,800[7] K
Other designations
V424 Lac, HR 8726, HD 216946, BD+48°3887, HIP 113288, SAO 52516
Database references
SIMBAD data

V424 Lacertae (V424 Lac) is a red supergiant variable star in the constellation Lacerta. It is a member of the Lacerta OB1 stellar association.

The MK spectral type of V424 Lac has been determined to be K5,[3] but it has also been classified as M0.[7] It was discovered to be slightly variable using analysis of Hipparcos photometry. The total range is less than a tenth of a magnitude.[9] Multiple short periods are detected, as well as slow variations with a period of 1,100 or 1,601 days. Although listed in the General Catalogue of Variable Stars as a slow irregular variable, it has been considered to be either a semiregular variable or long secondary period variable.[10]

There is an ultraviolet excess from V424 Lacertae, that may be due to an unseen companion, which could also explain the long secondary period. On this assumption, a sub-stellar companion in a 1,382 day 6.2 AU orbit has been suggested.[8]

References[edit]

  1. ^ a b c d e van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357. Vizier catalog entry
  2. ^ a b c 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. Bibcode:2002yCat.2237....0D. 
  3. ^ a b 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. 
  4. ^ 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. 
  5. ^ Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. 
  6. ^ Van Belle, G. T.; Creech-Eakman, M. J.; Hart, A. (2009). "Supergiant temperatures and linear radii from near-infrared interferometry". Monthly Notices of the Royal Astronomical Society 394 (4): 1925. Bibcode:2009MNRAS.394.1925V. doi:10.1111/j.1365-2966.2008.14146.x. 
  7. ^ a b c d e Levesque, Emily M.; Massey, Philip; Olsen, K. A. G.; Plez, Bertrand; Josselin, Eric; Maeder, Andre; Meynet, Georges (2005). "The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought". The Astrophysical Journal 628 (2): 973. arXiv:astro-ph/0504337. Bibcode:2005ApJ...628..973L. doi:10.1086/430901. 
  8. ^ a b c Lee, B.-C.; Han, I.; Park, M.-G.; Hatzes, A. P.; Kim, K.-M. (2014). "Low-amplitude and long-period radial velocity variations in giants HD 3574, 63 Cygni, and HD 216946". Astronomy & Astrophysics 566: A124. arXiv:1405.5955. Bibcode:2014A&A...566A.124L. doi:10.1051/0004-6361/201321863. 
  9. ^ Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. (1999). "The 74th Special Name-list of Variable Stars". Information Bulletin on Variable Stars 4659: 1. Bibcode:1999IBVS.4659....1K. 
  10. ^ Messina, Sergio (2007). "Evidence for the pulsational origin of the Long Secondary Periods: The red supergiant star V424 Lac (HD 216946)". New Astronomy 12 (7): 556. Bibcode:2007NewA...12..556M. doi:10.1016/j.newast.2007.04.002.