Chi Aquarii

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Chi Aquarii
Diagram showing star positions and boundaries of the Aquarius constellation and its surroundings
Cercle rouge 100%.svg
Location of χ Aquarii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Aquarius
Right ascension  23h 16m 50.93916s[1]
Declination −07° 43′ 35.4023″[1]
Apparent magnitude (V) +5.06[2]
Characteristics
Spectral type M3 III[3]
U−B color index +1.60[2]
B−V color index +1.60[2]
Variable type SRb?[4]
Astrometry
Radial velocity (Rv)–13.72 ± 0.86[5] km/s
Proper motion (μ) RA: −19.18[1] mas/yr
Dec.: −14.10[1] mas/yr
Parallax (π)5.32 ± 0.37[1] mas
Distance610 ± 40 ly
(190 ± 10 pc)
Absolute magnitude (MV)−1.43[6]
Details
Radius137[7] R
Other designations
χ Aqr, 92 Aquarii, BD−08 6076, HD 219576, HIP 114939, HR 8850, SAO 146612.[8]
Database references
SIMBADdata

Chi Aquarii, Latinized from χ Aquarii, is the Bayer designation of a star in the equatorial constellation of Aquarius. The distance to this star, based upon parallax measurements with a 7% margin of error, is roughly 610 light-years (190 parsecs),[1] it is visible to the naked eye with an apparent visual magnitude of +5.06.[2]

This is a red giant star with a spectral classification of M3 III;[3] the interferometry-measured angular diameter of this star is 6.70 ± 0.15 mas,[9] which, at its estimated distance, equates to a physical radius of about 137 times the radius of the Sun.[7] It is classified as a semi-regular variable star and its brightness varies by an amplitude of 0.0636 in magnitude.[10] The identified pulsation periods are 32.3, 38.5, and 44.9 days.[11]

References[edit]

  1. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
  2. ^ a b c d Nicolet, B. (1978), "Photoelectric photometric Catalogue of homogeneous measurements in the UBV System", Astronomy and Astrophysics Supplement Series, 34: 1–49, Bibcode:1978A&AS...34....1N.
  3. ^ a b Crampton, D.; Lloyd Evans, T. (1973), "Spectroscopic observations of M giant stars at the South Galactic Pole", Monthly Notices of the Royal Astronomical Society, 162: 11–15, Bibcode:1973MNRAS.162...11C, doi:10.1093/mnras/162.1.11.
  4. ^ Samus, N. N.; Durlevich, O. V.; 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. Bibcode:2009yCat....102025S.
  5. ^ Famaey, B.; et al. (May 2009), "Spectroscopic binaries among Hipparcos M giants. I. Data, orbits, and intrinsic variations", Astronomy and Astrophysics, 498 (2): 627–640, arXiv:0901.0934, Bibcode:2009A&A...498..627F, doi:10.1051/0004-6361/200810698.
  6. ^ 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.
  7. ^ a b Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
  8. ^ "chi Aqr -- Semi-regular pulsating Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-05.
  9. ^ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431: 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
  10. ^ Koen, Chris; Eyer, Laurent (March 2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331 (1): 45–59, arXiv:astro-ph/0112194, Bibcode:2002MNRAS.331...45K, doi:10.1046/j.1365-8711.2002.05150.x.
  11. ^ Tabur, V.; et al. (December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants", Monthly Notices of the Royal Astronomical Society, 400 (4): 1945–1961, arXiv:0908.3228, Bibcode:2009MNRAS.400.1945T, doi:10.1111/j.1365-2966.2009.15588.x.

External links[edit]