Astronomy:U Vulpeculae

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Short description: Variable star in the constellation Vulpecula
U Vulpeculae
UVulLightCurve.png
A visual band light curve for U Vulpeculae, adapted from Kiss (1998)[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Vulpecula
Right ascension  19h 36m 37.7281s[2]
Declination 20° 19′ 58.5692″[2]
Apparent magnitude (V) 6.73 - 7.54[3]
Characteristics
Spectral type F6Iab-G2[4]
Variable type δ Cep[3]
Astrometry
Proper motion (μ) RA: 0.906±0.050[2] mas/yr
Dec.: −0.960±0.062[2] mas/yr
Parallax (π)1.0530 ± 0.0390[2] mas
Distance3,100 ± 100 ly
(950 ± 40 pc)
Absolute magnitude (MV)-3.69[5]
Orbit[6]
Period (P)2,510 days
Eccentricity (e)0.675
Periastron epoch (T)2444800
Argument of periastron (ω)
(secondary)
353°
Semi-amplitude (K1)
(primary)
3.64 km/s
Details
Mass6.5[7] M
Radius60[7] R
Surface gravity (log g)1.75 - 1.85[8] cgs
Temperature5,655 - 5,965[8] K
Metallicity [Fe/H]0.09[9] dex
Age82[9] Myr
Other designations
BD+20° 4200, HD 185059, HIP 96458, HR 7458, SAO 87447[10]
Database references
SIMBADdata

U Vulpeculae is a variable and binary star in the constellation Vulpecula.

It is a classical Cepheid variable and its apparent magnitude ranges from 6.73 to 7.54 over a precise cycle of 7.99 days.[4] Its variable nature was discovered in 1898 at Potsdam Observatory by Gustav Müller and Paul Kempf.[11]

In 1991 a study of radial velocities showed that it U Vulpeculae is a spectroscopic binary and a full orbit with a period of 2510 days (6.9 years) was first calculated in 1996.[12][7] The secondary star is invisible and is only known from its effect on the motion of the primary.[6]

References

  1. Kiss, Laszlo L. (July 1998). "A photometric and spectroscopic study of the brightest northern Cepheids - I. Observations". Monthly Notices of the Royal Astronomical Society 297 (3): 825. doi:10.1046/j.1365-8711.1998.01559.x. Bibcode1998MNRAS.297..825K. 
  2. 2.0 2.1 2.2 2.3 2.4 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.
  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: B/gcvs. Bibcode2009yCat....102025S. 
  4. 4.0 4.1 Watson, Christopher (4 January 2010). "U Vulpeculae". AAVSO Website. American Association of Variable Star Observers. http://www.aavso.org/vsx/index.php?view=detail.top&oid=38179. 
  5. Kovtyukh, V. V.; Chekhonadskikh, F. A.; Luck, R. E.; Soubiran, C.; Yasinskaya, M. P.; Belik, S. I. (2010). "Accurate luminosities for F-G supergiants from FeII/FeI line depth ratios". Monthly Notices of the Royal Astronomical Society 408 (3): 1568. doi:10.1111/j.1365-2966.2010.17217.x. Bibcode2010MNRAS.408.1568K. 
  6. 6.0 6.1 Groenewegen, M. A. T. (2008). "Baade-Wesselink distances and the effect of metallicity in classical cepheids". Astronomy and Astrophysics 488 (1): 25–35. doi:10.1051/0004-6361:200809859. Bibcode2008A&A...488...25G. 
  7. 7.0 7.1 7.2 Imbert, M. (1996). "Cepheids and binarity. II. Radial velocities and spectroscopic orbits of four galactic Cepheids: RX Camelopardalis, MW Cygni, Z Lacertae and U Vulpeculae" (in fr). Astronomy and Astrophysics Supplement 116: 497–514. doi:10.1051/aas:1996312. Bibcode1996A&AS..116..497I. 
  8. 8.0 8.1 Andrievsky, S. M.; Lépine, J. R. D.; Korotin, S. A.; Luck, R. E.; Kovtyukh, V. V.; MacIel, W. J. (2013). "Barium abundances in Cepheids". Monthly Notices of the Royal Astronomical Society 428 (4): 3252. doi:10.1093/mnras/sts270. Bibcode2013MNRAS.428.3252A. 
  9. 9.0 9.1 Marsakov, V. A.; Koval', V. V.; Kovtyukh, V. V.; Mishenina, T. V. (2013). "Properties of the population of classical Cepheids in the Galaxy". Astronomy Letters 39 (12): 851. doi:10.1134/s1063773713120050. Bibcode2013AstL...39..851M. 
  10. "U Vulpeculae". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=U+Vulpeculae. 
  11. Müller, G.; Kempf, P. (1898). "Zwei neue Veränderliche von kurzer Periode" (in de). Astronomische Nachrichten 146 (3): 37–42. doi:10.1002/asna.18981460303. Bibcode1898AN....146...37M. https://zenodo.org/record/1424765/files/article.pdf. 
  12. Szabados, L. (1991). "Northern Cepheids: Period Update and Duplicity Effects". Communications of the Konkoly Observatory 11 part 3 (96): 123–244. Bibcode1991CoKon..96..123S. http://articles.adsabs.harvard.edu/full/1991CoKon..96..123S.