Astronomy:HD 192685

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Short description: B-type star in the constellation Vulpecula
HD 192685
Vulpecula constellation map.svg
Red circle.svg
Location of HD 192685 (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Vulpecula
Right ascension  20h 15m 15.89542s[1]
Declination 25° 35′ 31.0549″[1]
Apparent magnitude (V) 4.60 - 4.80[2]
Characteristics
Spectral type B3V[3]
U−B color index −0.73[4]
B−V color index −0.18[4]
Variable type γ Cas[2]
Astrometry
Radial velocity (Rv)−7.00[5] km/s
Proper motion (μ) RA: +6.93[1] mas/yr
Dec.: −3.89[1] mas/yr
Parallax (π)3.29 ± 0.51[1] mas
Distanceapprox. 1,000 ly
(approx. 300 pc)
Absolute magnitude (MV)−2.56[6]
Details
Mass8.0[7] M☉
Luminosity3331[6] L☉
Surface gravity (log g)3.49[8] cgs
Temperature18,700[9] K
Metallicity [Fe/H]−0.10[8] dex
Rotational velocity (v sin i)160[10] km/s
Other designations
QR Vul, BD+25°4165, CCDM J20153+2536AB, GC 28140, HIP 99824, HR 7739, HD 192685, SAO 88410, WDS J20153+2536AB
Database references
SIMBADdata

HD 192685, also known as QR Vulpeculae or HR 7739, is a Be star about 1,000 ly away in the Vulpecula constellation. It is visible to the naked eye.

Description

The main plot is a visual band light curve for QR Vulpeculae, adapted from Pavlovski et al. (1983),[11] showing a sudden brightening. The inset plot, adapted from Lefèvre et al. (2009),[12] shows the periodic variability.

HD 192685 varies slightly in brightness and is classified as a γ Cassiopeiae variable.[2]

From October to December 1982 the Hydrogen alpha absorption line increased in emission strength by 30%.[11] The line is partially filled by redshifted emission.[13]

HD 192685 has excess infrared emissions (12-100 μm) which are interpreted to be free-free radiation in the gas surrounding the star.[14]

Companions

It has at least one companion with separation 0.55" and magnitude 7.55,[15] and may also be a long-period spectroscopic binary.[16]

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. Bibcode: 2007A&A...474..653V.  Vizier catalog entry
  2. ↑ 2.0 2.1 2.2 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. Bibcode: 2009yCat....102025S. 
  3. ↑ Walker, G. A. H.; Yang, S.; Witt, A. N.; Fahlman, G. G. (Aug–Sep 1980). "The extinction of HD 200775 by dust in NGC 7023". Publications of the Astronomical Society of the Pacific 92: 414. doi:10.1086/130687. Bibcode: 1980PASP...92..411W. 
  4. ↑ 4.0 4.1 Mermilliod, J. C. (2006). "VizieR Online Data Catalog: Homogeneous Means in the UBV System (Mermilliod 1991)". VizieR On-line Data Catalog: II/168. Originally Published in: Institut d'Astronomie 2168. Bibcode: 2006yCat.2168....0M. Vizier catalog entry
  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. Bibcode: 2006AstL...32..759G. 
  6. ↑ 6.0 6.1 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode: 2012AstL...38..331A.  Vizier catalog entry
  7. ↑ Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society 410 (1): 190–200. doi:10.1111/j.1365-2966.2010.17434.x. Bibcode: 2011MNRAS.410..190T.  Vizier catalog entry
  8. ↑ 8.0 8.1 Wu, Yue; Singh, H. P.; Prugniel, P.; Gupta, R.; Koleva, M. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics 525: A71. doi:10.1051/0004-6361/201015014. Bibcode: 2011A&A...525A..71W. 
  9. ↑ Hohle, M.M.; Neuhäuser, R.; Schutz, B.F. (2010). "Masses and luminosities of O- and B-type stars and red supergiants". Astronomische Nachrichten 331 (4): 349. doi:10.1002/asna.200911355. Bibcode: 2010AN....331..349H.  Vizier catalog entry
  10. ↑ Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal 573 (1): 359–365. doi:10.1086/340590. Bibcode: 2002ApJ...573..359A. 
  11. ↑ 11.0 11.1 Pavlovski, K.; Bozic, H.; Harmanec, P.; Horn, J.; Koubsky, P. (14 November 1983). "Sudden Brightening of the Recently Discovered Be Star HR 7739". Information Bulletin on Variable Stars 2431 (1): 1. ISSN 0374-0676. Bibcode: 1983IBVS.2431....1P. 
  12. ↑ Lefèvre, L.; Marchenko, S. V.; Moffat, A. F. J.; Acker, A. (November 2009). "A systematic study of variability among OB-stars based on HIPPARCOS photometry". Astronomy and Astrophysics 507 (2): 1141–1201. doi:10.1051/0004-6361/200912304. Bibcode: 2009A&A...507.1141L. 
  13. ↑ Green, Daniel W. E. (July 14, 1982). "2 Vul AND HR 7739". IAU Circular (IAU Central Bureau for Astronomical Telegrams) 3710. http://www.cbat.eps.harvard.edu/iauc/03700/03710.html#Item2. Retrieved 11 December 2012. 
  14. ↑ Cote, J. (July 1987). "B and A type stars with unexpectedly large colour excesses at IRAS wavelengths". Astronomy and Astrophysics 181 (1): 83. ISSN 0004-6361. Bibcode: 1987A&A...181...77C. 
  15. ↑ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode: 2008MNRAS.389..869E.  Vizier catalog entry
  16. ↑ Mason, Brian D.; Wycoff, Gary L.; Hartkopf, William I.; Douglass, Geoffrey G.; Worley, Charles E. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal 122 (6): 3466. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M.  Vizier catalog entry

External links



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