Astronomy:HD 40409

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Short description: Astrometric binary star system in the constellation Dorado
HD 40409
Observation data
Equinox J2000.0]] (ICRS)
Constellation Dorado
Right ascension  05h 54m 06.05633s[1]
Declination −63° 05′ 23.1963″[1]
Apparent magnitude (V) 4.65[2]
Characteristics
Spectral type K2 III[3]
B−V color index 1.022±0.045[2]
Astrometry
Radial velocity (Rv)+25.1±0.8[2] km/s
Proper motion (μ) RA: +118.57[1] mas/yr
Dec.: +572.93[1] mas/yr
Parallax (π)36.9551 ± 0.2499[1] mas
Distance88.3 ± 0.6 ly
(27.1 ± 0.2 pc)
Absolute magnitude (MV)2.56[2]
Details[4]
Mass1.12 M
Radius4.79 R
Luminosity11.2 L
Surface gravity (log g)3.27 cgs
Temperature4,858 K
Metallicity [Fe/H]+0.07 dex
Age7.91 Gyr
Other designations
CD−63°218, FK5 2452, GJ 9194, HD 40409, HIP 27890, HR 2102, SAO 249390[5]
Database references
SIMBADdata

HD 40409 is a suspected astrometric binary[6] star system in the southern constellation of Dorado. It is a faint system but visible to the naked eye with an apparent visual magnitude of 4.65.[2] Based upon an annual parallax shift of 36.96 mas,[1] it is located 88 light years away from the Sun. It is moving further away with a heliocentric radial velocity of +25 km/s.[2] The system has a relatively high proper motion, traversing the celestial sphere at the rate of 0.57 arcseconds per year along a position angle of 14.51°.[7]

Based on the stellar classification of K2 III assigned by Gray et al. (2006),[3] the visible component is a K-type giant star. In contrast, Keenan and McNeil (1989) gave it a somewhat less evolved classification of K2 III–IV.[8] It is about eight billion years old with 12% more mass than the Sun, and has expanded to 4.8 times the Sun's radius. The star is radiating 11 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,858 K.[4]

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. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 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 Gray, R. O. et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal 132 (1): 161–170, doi:10.1086/504637, Bibcode2006AJ....132..161G. 
  4. 4.0 4.1 Wittenmyer, Robert A.; Liu, Fan; Wang, Liang; Casagrande, Luca; Johnson, John Asher; Tinney, C. G. (July 2016), "The Pan-Pacific Planet Search. V. Fundamental Parameters for 164 Evolved Stars", The Astronomical Journal 152 (1): 15, doi:10.3847/0004-6256/152/1/19, 19, Bibcode2016AJ....152...19W. 
  5. "HD 40409". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+40409. 
  6. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  7. Bakos, Gáspár Á. et al. (July 2002), "Revised Coordinates and Proper Motions of the Stars in the Luyten Half-Second Catalog", The Astrophysical Journal Supplement Series 141 (1): 187–193, doi:10.1086/340115, Bibcode2002ApJS..141..187B. 
  8. Keenan, Philip C.; McNeil, Raymond C. (1989), "The Perkins catalog of revised MK types for the cooler stars", Astrophysical Journal Supplement Series 71: 245, doi:10.1086/191373, Bibcode1989ApJS...71..245K.