Astronomy:62 Sagittarii

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Short description: Star in the constellation of Sagittarius
62 Sagittarii
Terebellum asterism.png
The four stars of the Terebellum
Observation data
Equinox J2000.0]] (ICRS)
Constellation Sagittarius
Right ascension  20h 02m 39.48097s[1]
Declination −27° 42′ 35.4443″[1]
Apparent magnitude (V) 4.45 to 4.64[2]
Characteristics
Spectral type M4.5III[3]
U−B color index +1.80[4]
B−V color index +1.65[4]
R−I color index +1.56[4]
Variable type LB[2]
Astrometry
Radial velocity (Rv)+9.9±0.8[5] km/s
Proper motion (μ) RA: +32.97[1] mas/yr
Dec.: +14.00[1] mas/yr
Parallax (π)7.27 ± 0.18[1] mas
Distance450 ± 10 ly
(138 ± 3 pc)
Absolute magnitude (MV)−1.26[6]
Details
Radius72+16
−6
[7] R
Luminosity1,107±74[7] L
Temperature3,915+168
−380
[7] K
Rotational velocity (v sin i)1.5±1.5[8] km/s
Other designations
c Sgr, 62 Sgr, V3872 Sagittarii, CD−28°16355, CPD−28°7105, FK5 753, GC 27763, HD 189763, HIP 98688, HR 7650, SAO 188844, PPM 270603[9]
Database references
SIMBADdata

62 Sagittarii is a single,[10] variable star in the constellation of Sagittarius. It has the Bayer designation c Sagittarii and the variable star designation V3872 Sagittarii, while 62 Sagittarii is its Flamsteed designation. This object forms the southwest corner of the asterism called the Terebellum. It is visible to the naked eye with an apparent visual magnitude that varies between 4.45 and 4.64,[2] and, at its peak, it is the brightest of the four stars in the Terebellum. 62 Sagittarii is the star in the Terebellum which is most distant from its centre; it is 1.72° from its northwest corner, 60 Sagittarii, and 1.37° from its southeast corner, 59 Sagittarii. This star is located approximately 450 light-years from the Sun based on parallax,[1] and is drifting further away with a radial velocity of +10 km/s.[5]

A visual band light curve for V3872 Sagittarii, adapted from data published by Tabur et al. (2009)[11]

This is an aging red giant with a stellar classification of M4.5III,[3] a star that has exhausted the supply of hydrogen at its core and expanded to around 72[7] times the Sun's radius. It is a slow irregular variable with multiple pulsation periods.[11] The star is radiating about 1,100[7] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 3,915 K.[7]

Pulsation periods of 62 Sagittarii[11]
Period (days) 24.0 30.4 31.3 42.8 50.5 234.7
Amplitude (mag.) 0.027 0.019 0.043 0.042 0.022 0.018

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 database entry, The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars , Sternberg Astronomical Institute, Moscow, Russia. Accessed on line November 19, 2009.
  3. 3.0 3.1 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. 
  4. 4.0 4.1 4.2 Hoffleit, D.; Warren, Jr., W. H., "V3872 Sgr, database record", The Bright Star Catalogue (5th Revised ed.), CDS, http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=V/50/catalog&recno=7650.  ID V/50. Accessed on line November 19, 2009.
  5. 5.0 5.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode2006AstL...32..759G. 
  6. Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos com/pilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. 7.0 7.1 7.2 7.3 7.4 7.5 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.
  8. Zamanov, R. K. et al. (October 2008), "Rotational velocities of the giants in symbiotic stars - III. Evidence of fast rotation in S-type symbiotics", Monthly Notices of the Royal Astronomical Society 390 (1): 377–382, doi:10.1111/j.1365-2966.2008.13751.x, Bibcode2008MNRAS.390..377Z. 
  9. "62 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=62+Sgr. 
  10. Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  11. 11.0 11.1 11.2 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, doi:10.1111/j.1365-2966.2009.15588.x, Bibcode2009MNRAS.400.1945T.