3 Vulpeculae

A light curve for V377 Vulpeculae, plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Vulpecula
Right ascension 19h 22m 50.88540s[2]
Declination +26° 15′ 44.6676″[2]
Apparent magnitude (V) 5.18[3]
Characteristics
Spectral type B6 III[4]
B−V color index −0.119±0.001[3]
Variable type SPB[5][6]
Astrometry
Radial velocity (Rv)−14.1±1.1[3] km/s
Proper motion (μ) RA: +1.081[2] mas/yr
Dec.: −10.270[2] mas/yr
Parallax (π)9.0575 ± 0.1967 mas[2]
Distance360 ± 8 ly
(110 ± 2 pc)
Absolute magnitude (MV)−0.17[3]
Orbit[5]
Period (P)367.7
Eccentricity (e)0.15
Semi-amplitude (K1)
(primary)		6.8 km/s
Details
A
Mass4.16[5] M☉
Luminosity286+64
−52[7] L☉
Surface gravity (log g)4.30[5] cgs
Temperature14,343[5] K
Rotational velocity (v sin i)15.5[8] km/s
B
Mass0.6 - 1.1[5] M☉
Age25[5] Myr
Other designations
3 Vul, V377 Vulpeculae, BD+25°3811, GC 26748, HD 182255, HIP 95260, HR 7358, SAO 87136[9]
Database references
SIMBADdata

3 Vulpeculae (abbreviated 3 Vul) is a binary star system in the northern constellation of Vulpecula,[9] located around 360 light years away from the Sun.[2] 3 Vulpeculae is its Flamsteed designation. It is visible to the naked eye as a faint, blue-white hued star with a baseline apparent visual magnitude of 5.18.[3]

3 Vul has been nicknamed "the Observer's Nightmare" (or its Latin free translation, "Spectatori Error Inextricabilis") by some astronomers[10][5] because it is difficult to study as its orbital period is close to a year, and additionally it is pulsating with a period close to a day.[5] From a twenty-year spectroscopic study, Hube and Aikman established a 367-day orbital period, and noted the presence of non-radial pulsations in the primary star. From sparse photometry, the authors also established the star's light variability. They suggested that the primary is a member of the 53 Persei class of variable stars.[11] Such stars are now collectively known by the term slowly pulsating B-type stars. It's photometric variation led to a variable star designation, as V377 Vulpeculae, but the non-reproducibility of the light curve made determination of the pulsation period elusive.

Continuous monitoring of the star by the Transiting Exoplanet Survey Satellite has revealed a beat-period phenomenon in the light curve, which causes the luminosity variations to fluctuate in amplitude. The pulsations are non-radial, that is, the star's photosphere varies in shape rather than volume; different parts of the star are expanding and contracting simultaneously. These gravity waves, or g-mode waves, can be indicative of the interior structure of the star.[citation needed]

The primary member, designated component A, is a most likely a B-type main-sequence star[7] with a stellar classification of B6 III.[4] The star has 4.16[5] times the mass of the Sun and is radiating 286[7] times the Sun's luminosity from its photosphere at an effective temperature of 14,343 K.[5] The secondary has an estimated 0.6–1.1 solar masses.[5]

References

  1. ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
  2. ^ a b c d e f Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
  3. ^ a b c d e 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.
  4. ^ a b Cucchiaro, A.; Macau-Hercot, D.; Jaschek, M.; Jaschek, C. (1977). "Spectral classification from the ultraviolet line features of S2/68 spectra. II - Late B-type stars". Astronomy and Astrophysics Supplement Series. 30: 71. Bibcode:1977A&AS...30...71C.
  5. ^ a b c d e f g h i j k l Dukes, Robert; Kubinec, William; Kubinec, Angela; Adelman, Saul (2003). "A Photometric and Spectroscopic Study of 3 Vulpeculae: An Observer's Nightmare". The Astronomical Journal. 126 (1): 370. Bibcode:2003AJ....126..370D. doi:10.1086/375463.
  6. ^ Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
  7. ^ a b c Walczak, P.; et al. (December 2012). "Constraints on stellar parameters of the slowly pulsating B star HD 182255 from complex asteroseismology". Astronomische Nachrichten. 333 (10): 1065. arXiv:1212.4643. Bibcode:2012AN....333.1065W. doi:10.1002/asna.201211824. S2CID 116926922.
  8. ^ Zverko, J.; Romanyuk, I.; Iliev, I.; Kudryavtsev, D.; Stateva, I.; Semenko, E. (April 2016). "Stars with discrepant v sin i as derived from the Ca II λ3933 Å and Mg II λ4481 Å lines. V. HD 182255 and HD 214923—SPB stars in binary systems". Astrophysical Bulletin. 71 (2): 199–207. Bibcode:2016AstBu..71..199Z. doi:10.1134/S1990341316020073. S2CID 124871780.
  9. ^ a b "3 Vul". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-03-13.
  10. ^ Kaler, Jim. "3 Vul". Retrieved 2016-08-09.
  11. ^ Hube, Douglas P.; Aikman, G. C. L. (1991). "3 Vulpeculae: A non-radial pulsator in a one-year binary system". Publications of the Astronomical Society of the Pacific. 103 (659): 49-62. Bibcode:1991PASP..103...49H. doi:10.1086/132794.
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