HD 192685

Last updated
HD 192685
Vulpecula constellation map.svg
Red circle.svg
Location of HD 192685 (circled)
Observation data
Epoch J2000       Equinox J2000
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  mas [1]
Distance approx. 1,000  ly
(approx. 300  pc)
Absolute magnitude  (MV)−2.56 [6]
Details
Mass 8.0 [7]   M
Luminosity 3331 [6]   L
Surface gravity (log g)3.49 [8]   cgs
Temperature 18,700 [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
SIMBAD data

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.

Contents

Description

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

In 1982 Krešimir Pavlovski and Hrvoje Božić announced their discovery that HD 192685 is a variable star. [13] It was given its variable star designation, QR Vulpeculae, in 1985. [14] 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. [15]

HD 192685 has excess infrared emissions (12-100 μm) which are interpreted to be free-free radiation in the gas surrounding the star. [16]

Companions

It has at least one companion with separation 0.55" and magnitude 7.55, [17] and may also be a long-period spectroscopic binary. [18]

References

  1. 1 2 3 4 5 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. S2CID   18759600. Vizier catalog entry
  2. 1 2 3 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. 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. Bibcode:1980PASP...92..411W. doi: 10.1086/130687 .
  4. 1 2 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. arXiv: 1606.08053 . Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. S2CID   119231169.
  6. 1 2 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv: 1108.4971 . Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. S2CID   119257644. 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. arXiv: 1007.4883 . Bibcode:2011MNRAS.410..190T. doi: 10.1111/j.1365-2966.2010.17434.x . S2CID   118629873. Vizier catalog entry
  8. 1 2 Wu, Yue; Singh, H. P.; Prugniel, P.; Gupta, R.; Koleva, M. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics. 525: A71. arXiv: 1009.1491 . Bibcode:2011A&A...525A..71W. doi:10.1051/0004-6361/201015014. S2CID   53480665.
  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. arXiv: 1003.2335 . Bibcode:2010AN....331..349H. doi:10.1002/asna.200911355. S2CID   111387483. Vizier catalog entry
  10. Abt, Helmut A.; Levato, Hugo; Grosso, Monica (2002). "Rotational Velocities of B Stars". The Astrophysical Journal. 573 (1): 359–365. Bibcode:2002ApJ...573..359A. doi: 10.1086/340590 .
  11. 1 2 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. Bibcode:1983IBVS.2431....1P. ISSN   0374-0676.
  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. Bibcode:2009A&A...507.1141L. doi: 10.1051/0004-6361/200912304 .
  13. Pavlovski, Pavlovski; Božić, Hrvoje (1982). "UBV Photometry of some Be stars: progress report". Hvar Observatory Bulletin. 6: 45–51. Bibcode:1982HvaOB...6...45P . Retrieved 13 August 2025.
  14. Kholopov, P. N.; Samus, N. N.; Kazarovets, E. V.; Perova, N. B. (March 1985). "The 67th Name-List of Variable Stars". Information Bulletin on Variable Stars. 2681: 1–32. Bibcode:1985IBVS.2681....1K . Retrieved 13 August 2025.
  15. Green, Daniel W. E. (July 14, 1982). "2 Vul AND HR 7739". IAU Circular (3710). IAU Central Bureau for Astronomical Telegrams. Retrieved 11 December 2012.
  16. Cote, J. (July 1987). "B and A type stars with unexpectedly large colour excesses at IRAS wavelengths". Astronomy and Astrophysics . 181 (1): 83. Bibcode:1987A&A...181...77C. ISSN   0004-6361.
  17. 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. arXiv: 0806.2878 . Bibcode:2008MNRAS.389..869E. doi: 10.1111/j.1365-2966.2008.13596.x . S2CID   14878976. Vizier catalog entry
  18. 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. Bibcode:2001AJ....122.3466M. doi: 10.1086/323920 . Vizier catalog entry