Astronomy:Iota Aquarii

From HandWiki
Short description: B-type main sequence star in the constellation Aquarius
Iota Aquarii
Aquarius IAU.svg
Red circle.svg
Location of ι Aquarii (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquarius
Right ascension  22h 06m 26.22742s[1]
Declination –13° 52′ 10.8615″[1]
Apparent magnitude (V) 4.279[2]
Characteristics
Spectral type B8 V[3]
U−B color index –0.288[2]
B−V color index –0.062[2]
Variable type constant[4]
Astrometry
Radial velocity (Rv)–10.0[5] km/s
Proper motion (μ) RA: +36.89[1] mas/yr
Dec.: –58.99[1] mas/yr
Parallax (π)18.62 ± 0.22[1] mas
Distance175 ± 2 ly
(53.7 ± 0.6 pc)
Absolute magnitude (MV)+0.64[6]
Details[7]
A
Mass3.20+0.20
−0.16 M☉
Radius2.7[8] R☉
Luminosity74[6] L☉
Surface gravity (log g)4.09±0.08[9] cgs
Temperature11,284±284[8] K
Metallicity [Fe/H]−0.08±0.12[9] dex
Rotational velocity (v sin i)135[10] km/s
Age124+37
−62 Myr
B
Mass1.00±0.03 M☉
Temperature5,710±112 K
Rotational velocity (v sin i)20 km/s
Other designations
ι Aqr, 33 Aquarii, BD–14 6209, FK5 828, HD 209819, HIP 109139, HR 8418, SAO 164861[11]
Database references
SIMBADdata

Iota Aquarii, Latinised from ι Aquarii, is the Bayer designation for a binary star[7] system in the equatorial constellation of Aquarius. It is visible to the naked eye with an apparent magnitude of +4.279.[2] Based upon parallax measurements made during the Hipparcos mission, the distance to this star is around 175 light-years (54 parsecs).[2] The system is drifting closer to the Sun with a radial velocity of −10 km/s.[5]

The binary nature of this system was reported in 2009 following a radial velocity survey using the HARPS instrument.[4] A 2010 infrared search for companions around this star was unsuccessful.[12] The presence of a stellar companion was confirmed through direct spectral detection in 2016. The companion shows a significant velocity variation over a 77-day interval, suggesting a short orbital period.[7]

The spectrum of the primary, component A, fits a stellar classification of B8 V,[3] showing that this is a B-type main-sequence star. It is roughly 124[7] million years old and is spinning rapidly with a projected rotational velocity of 135 km/s.[10] The star has 3.2[7] times the mass of the Sun and 2.7[8] times the Sun's radius. It is radiating 74[6] times the luminosity of the Sun from its photosphere at an effective temperature of ~11,284 km/s.[8] The secondary, component B, has a spectrum of a solar-mass star.[7] The system is a source for X-ray emission.[13]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V. 
  2. ↑ 2.0 2.1 2.2 2.3 2.4 Kozok, J. R. (September 1985), "Photometric observations of emission B-stars in the southern Milky Way", Astronomy and Astrophysics Supplement Series 61: 387–405, Bibcode: 1985A&AS...61..387K. 
  3. ↑ 3.0 3.1 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H. 
  4. ↑ 4.0 4.1 Lagrange, A. -M. et al. (2009), "Extrasolar planets and brown dwarfs around A-F type stars. VI. High precision RV survey of early type dwarfs with HARPS", Astronomy & Astrophysics 495 (1): 335–352, doi:10.1051/0004-6361:200810105, Bibcode: 2009A&A...495..335L. 
  5. ↑ 5.0 5.1 Wielen, R. et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg (Astronomisches Rechen-Institut Heidelberg) 35 (35): 1, Bibcode: 1999VeARI..35....1W. 
  6. ↑ 6.0 6.1 6.2 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A. 
  7. ↑ 7.0 7.1 7.2 7.3 7.4 7.5 Gullikson, Kevin et al. (August 2016), "The Close Companion Mass-ratio Distribution of Intermediate-mass Stars", The Astronomical Journal 152 (2): 13, doi:10.3847/0004-6256/152/2/40, 40, Bibcode: 2016AJ....152...40G. 
    Note: the observations were made on modified Julian dates 6447.91 and 6524.67, which are separated by 76.76 days.
  8. ↑ 8.0 8.1 8.2 8.3 Underhill, A. B. et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society 189 (3): 601–605, doi:10.1093/mnras/189.3.601, Bibcode: 1979MNRAS.189..601U. 
  9. ↑ 9.0 9.1 Wu, Yue et al. (January 2011), "Coudé-feed stellar spectral library - atmospheric parameters", Astronomy and Astrophysics 525: A71, doi:10.1051/0004-6361/201015014, Bibcode: 2011A&A...525A..71W. 
  10. ↑ 10.0 10.1 Abt, Helmut A.; Levato, Hugo; Grosso, Monica (July 2002), "Rotational Velocities of B Stars", The Astrophysical Journal 573 (1): 359–365, doi:10.1086/340590, Bibcode: 2002ApJ...573..359A. 
  11. ↑ "* iot Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+iot+Aqr. 
  12. ↑ Ehrenreich, D. et al. (November 2010), "Deep infrared imaging of close companions to austral A- and F-type stars", Astronomy and Astrophysics 523: A73, doi:10.1051/0004-6361/201014763, Bibcode: 2010A&A...523A..73E. 
  13. ↑ Haakonsen, Christian Bernt; Rutledge, Robert E. (September 2009), "XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources", The Astrophysical Journal Supplement 184 (1): 138–151, doi:10.1088/0067-0049/184/1/138, Bibcode: 2009ApJS..184..138H. 

External links



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Iota_Aquarii&oldid=3427350"