Astronomy:Beta Gruis

From HandWiki
Short description: Star in the constellation of Grus
Beta Gruis
Grus constellation map.svg
Red circle.svg
Location of β Gruis (circled)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Grus
Right ascension  22h 42m 40.05027s[1]
Declination −46° 53′ 04.4752″[1]
Apparent magnitude (V) 2.146[2] (2.0 - 2.3[3])
Characteristics
Evolutionary stage AGB[4]
Spectral type M5 III[5]
U−B color index +1.757[2]
B−V color index +1.620[2]
Variable type SRb[3]
Astrometry
Radial velocity (Rv)+1.6[6] km/s
Proper motion (μ) RA: +135.16[1] mas/yr
Dec.: −4.38[1] mas/yr
Parallax (π)18.43 ± 0.42[1] mas
Distance177 ± 4 ly
(54 ± 1 pc)
Absolute magnitude (MV)−1.61±0.052[7]
Details
Mass2.4[8] M☉
Radius180[9] R☉
Luminosity2,500[9] L☉
Surface gravity (log g)0.4[9] cgs
Temperature3,480[10] K
Metallicity [Fe/H]0.0[9] dex
Other designations
Tiaki, Beta Gru, CD−47 14308, FK5 856, HR 8636, HD 214952, HIP 112122, SAO 231258.[11]
Database references
SIMBADdata

Beta Gruis (β Gruis, abbreviated Beta Gru, β Gru), formally named Tiaki /tiˈɑːki/,[12] is the second brightest star in the southern constellation of Grus. It was once considered the rear star in the tail of the constellation of the (Southern) Fish, Piscis Austrinus: it, with Alpha, Delta, Theta, Iota, and Lambda Gruis, belonged to Piscis Austrinus in medieval Arabic astronomy.[13]

Nomenclature

β Gruis (Latinised to Beta Gruis) is the star's Bayer designation.

It bore the traditional Tuamotuan name of Tiaki.[14] In 2016, the IAU organized a Working Group on Star Names (WGSN)[15] to catalog and standardize proper names for stars. The WGSN approved the name Tiaki for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[12]

In Chinese, 鶴 (Hè), meaning Crane, refers to an asterism consisting of Beta Gruis, Alpha Gruis, Epsilon Gruis, Eta Gruis, Delta Tucanae, Zeta Gruis, Iota Gruis, Theta Gruis, Delta² Gruis and Mu¹ Gruis.[16] Consequently, Beta Gruis itself is known as 鶴二 (Hè èr, English: Second Star of the Crane).[17] The Chinese name gave rise to another English name, Ke.[18]

Properties

A visual band light curve for Beta Gruis, plotted from data published by Otero and Moon (2006).[3] The inset plot shows the points plotted in red with an expanded scale.

This is a red giant star[3] on the asymptotic giant branch[4] with an estimated mass of about 2.4 times that of the Sun and a surface temperature of approximately 3,480 K,[10] just over half the surface temperature of the Sun. This low temperature accounts for the dull red color of an M-type star. The total luminosity is about 2,500 times that of the Sun, and it has estimated 180 times the Sun's radius.[8]

Beta Gruis is a semiregular variable (SRb) star that varies in magnitude by about 0.4. It varies between intervals when it displays regular changes with a 37-day periodicity and times when it undergoes slow irregular variability.[3]

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 Gutierrez-Moreno, Adelina et al. (1966), "A System of photometric standards", Publ. Dept. Astron. Univ. Chile (Publicaciones Universidad de Chile, Department de Astronomy) 1: 1–17, Bibcode: 1966PDAUC...1....1G 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 Otero, S. A.; Moon, T. (December 2006), "The Characteristic Period of Pulsation of β Gruis", The Journal of the American Association of Variable Star Observers 34 (2): 156–164, Bibcode: 2006JAVSO..34..156O 
  4. ↑ 4.0 4.1 Eggen, Olin J. (July 1992). "Asymptotic giant branch stars near the sun". Astronomical Journal 104 (1): 275–313. doi:10.1086/116239. Bibcode: 1992AJ....104..275E. 
  5. ↑ Houk, Nancy (1978), "Michigan catalogue of two-dimensional spectral types for the HD stars", Ann Arbor: Dept. Of Astronomy (Ann Arbor: Dept. of Astronomy, University of Michigan) 2, Bibcode: 1978mcts.book.....H 
  6. ↑ Wielen, R. et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb (Astronomisches Rechen-Institut Heidelberg) 35 (35): 1, Bibcode: 1999VeARI..35....1W 
  7. ↑ Park, Sunkyung et al. (2013), "Wilson-Bappu Effect: Extended to Surface Gravity", The Astronomical Journal 146 (4): 73, doi:10.1088/0004-6256/146/4/73, Bibcode: 2013AJ....146...73P. 
  8. ↑ 8.0 8.1 Gondoin, P. (December 1999), "Evolution of X-ray activity and rotation on G-K giants", Astronomy and Astrophysics 352: 217–227, Bibcode: 1999A&A...352..217G 
  9. ↑ 9.0 9.1 9.2 9.3 Judge, P. G. (November 1986), "Constraints on the Outer Atmospheric Structure of Late Type Giant Stars with IUE Application to Alpha-Tauri K5III and Beta-Gruis M5III", Monthly Notices of the Royal Astronomical Society 223 (2): 239, doi:10.1093/mnras/223.2.239, Bibcode: 1986MNRAS.223..239J 
  10. ↑ 10.0 10.1 Engelke, Charles W.; Price, Stephan D.; Kraemer, Kathleen E. (October 2006), "Spectral Irradiance Calibration in the Infrared. XVI. Improved Accuracy in the Infrared Spectra of the Secondary and Tertiary Standard Calibration Stars", The Astronomical Journal 132 (4): 1445–1463, doi:10.1086/505865, Bibcode: 2006AJ....132.1445E 
  11. ↑ "V* bet Gru -- Variable Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Gruis, retrieved 2010-01-05 
  12. ↑ 12.0 12.1 "Naming Stars". IAU.org. https://www.iau.org/public/themes/naming_stars/. Retrieved 16 December 2017. 
  13. ↑ Allen, R. H. (1963), Star Names: Their Lore and Meaning (rep ed.), New York City , NY: Dover Publications Inc., p. 238, ISBN 0-486-21079-0 
  14. ↑ "WG Triennial Report (2015-2018) - Star Names". p. 7. https://www.iau.org/static/science/scientific_bodies/working_groups/280/wg-starnames-triennial-report-2015-2018.pdf. Retrieved 2018-07-14. 
  15. ↑ "IAU Working Group on Star Names (WGSN)". https://www.iau.org/science/scientific_bodies/working_groups/280/. Retrieved 22 May 2016. 
  16. ↑ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN:978-986-7332-25-7.
  17. ↑ (in Chinese) 香港太空館 - 研究資源 - 亮星中英對照表 , Hong Kong Space Museum. Accessed on line November 23, 2010.
  18. ↑ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Grus

External links


Coordinates: Sky map 22h 42m 40.1s, −46° 53′ 05″



Retrieved from "https://handwiki.org/wiki/index.php?title=Astronomy:Beta_Gruis&oldid=3423367"