Astronomy:26 Vulpeculae

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Short description: Binary star system in the constellation Vulpecula
26 Vulpeculae
Observation data
Equinox J2000.0]] (ICRS)
Constellation Vulpecula
Right ascension  20h 36m 08.3399s[1]
Declination +25° 52′ 57.5615″[1]
Apparent magnitude (V) 6.40[2]
Characteristics
Spectral type A5 III[3]
B−V color index 0.158±0.005[2]
Astrometry
Radial velocity (Rv)−63.4±2.3[4] km/s
Proper motion (μ) RA: +26.010[1] mas/yr
Dec.: +12.189[1] mas/yr
Parallax (π)5.0684 ± 0.0346[1] mas
Distance644 ± 4 ly
(197 ± 1 pc)
Absolute magnitude (MV)−0.04[2]
Orbit[5]
Period (P)11.088 d
Eccentricity (e)0.28
Periastron epoch (T)2,426,492.6090 JD
Argument of periastron (ω)
(secondary)
50.1°
Semi-amplitude (K1)
(primary)
58.7 km/s
Details
Radius4.6[6] R
Luminosity79.75[7] L
Temperature7,888[7] K
Rotational velocity (v sin i)15[8] km/s
Other designations
26 Vul, BD+25°4299, HD 196362, HIP 101641, HR 7874, SAO 88884[9]
Database references
SIMBADdata

26 Vulpeculae is a close binary star[5] system in the northern constellation of Vulpecula,[9] around 644 light years away from the Sun.[1] It is a challenge to view with the naked eye, having an apparent visual magnitude of 6.40.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −63 km/s,[4] and is expected to come within 225 light-years in around 2.6 million years.[2]

This is a single-lined spectroscopic binary with an orbital period of 11 days and an eccentricity of 0.28.[5] The visible component is a suspected chemically peculiar star[10] with a stellar classification of A5 III,[3] suggesting this is an evolved giant star. It has about 4.6[6] times the Sun's radius and is radiating 80 times the Sun's luminosity from its photosphere at an effective temperature of 7,888 K.[7]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 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.
  2. 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Cowley, A. et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal 74: 375–406, doi:10.1086/110819, Bibcode1969AJ.....74..375C 
  4. 4.0 4.1 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, Bibcode2006AstL...32..759G. 
  5. 5.0 5.1 5.2 Pourbaix, D. et al. (2004), "SB9: The Ninth Catalogue of Spectroscopic Binary Orbits", Astronomy & Astrophysics 424: 727–732, doi:10.1051/0004-6361:20041213, Bibcode2004A&A...424..727P. 
  6. 6.0 6.1 Pasinetti Fracassini, L. E. et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics 367: 521–524, doi:10.1051/0004-6361:20000451, Bibcode2001A&A...367..521P. 
  7. 7.0 7.1 7.2 McDonald, I. et al. (2012), "Fundamental parameters and infrared excesses of Hipparcos stars", Monthly Notices of the Royal Astronomical Society 427 (1): 343–357, doi:10.1111/j.1365-2966.2012.21873.x, Bibcode2012MNRAS.427..343M. 
  8. Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393 (3): 897–911, doi:10.1051/0004-6361:20020943, Bibcode2002A&A...393..897R. 
  9. 9.0 9.1 "26 Vul". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=26+Vul. 
  10. Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics 498 (3): 961–966, doi:10.1051/0004-6361/200810788, Bibcode2009A&A...498..961R, https://zenodo.org/record/890529/files/article.pdf. 

External links