52 Sagittarii

52 Sagittarii is a binary star[12] system in the southern constellation of Sagittarius. It has the Bayer designation h2 Sagittarii, while 52 Sagittarii is the Flamsteed designation. This system is visible to the naked eye as a faint, blue-white hued point of light with an apparent visual magnitude of 4.59.[2] It is located approximately 190 light years away based on parallax,[1] but is drifting closer with a radial velocity of −19 km/s.[6]

52 Sagittarii
Location of 52 Sagittarii (circled)
Observation data
Epoch J2000      Equinox J2000
Constellation Sagittarius
Right ascension  19h 36m 42.43288s[1]
Declination −24° 53′ 01.0288″[1]
Apparent magnitude (V) 4.59[2] + 9.2
Characteristics
Evolutionary stage main sequence[3]
Spectral type B8/9V[4] + K2–4V
U−B color index −0.15[5]
B−V color index −0.06[5]
Astrometry
Radial velocity (Rv)−19.00[6] km/s
Proper motion (μ) RA: +68.30[1] mas/yr
Dec.: −21.51[1] mas/yr
Parallax (π)17.20 ± 0.23[1] mas
Distance190 ± 3 ly
(58.1 ± 0.8 pc)
Absolute magnitude (MV)0.77[2]
Details
52 Sgr A
Mass3.0±0.1[7] M☉
Radius2.1[8] R☉
Luminosity60.5+1.9
−1.8[3] L☉
Surface gravity (log g)4.19[9] cgs
Temperature10,592+74
−72[3] K
Metallicity [Fe/H]0.00[10] dex
Rotational velocity (v sin i)48[3] km/s
Age57.3±11.7[7] Myr
Other designations
h2 Sgr, 52 Sgr, NSV 12191, CD−25°14184, GC 27089, HD 184707, HIP 96465, HR 7440, SAO 188337, CCDM J19367-2453AB, WDS J19367-2453AB, GSC 06893-02132[11]
Database references
SIMBADdata

The primary component is a B-type main-sequence star with a stellar classification of B8/9V.[4] Garrison and Gray (1994) assigned it a class of kB8 hB9 HeA0 Va (Sr Fe II),[13] displaying the calcium K line of a B8 class star, the hydrogen lines of a B9 star, and the helium lines of an A0 star, along with overabundances of strontium and iron. It is around 57[7] million years old with three[7] times the mass of the Sun and about 2.1[8] times the Sun's radius. It is radiating 60.5[3] times the luminosity of the Sun from its photosphere at an effective temperature of 10,592 K.[3] The star is spinning with a projected rotational velocity of 48 km/s.[3]

52 Sagittarii has one companion at an angular separation of 2.4″. This object is magnitude 9.2 with a spectral class in the K2V-K4V range, and is believed to be the source of X-ray emissions from the system.[14][15]

References
  1. Van Leeuwen, F. (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. Vizier catalog entry
  2. 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. Vizier catalog entry
  3. Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars". Astronomy & Astrophysics. 537: A120. arXiv:1201.2052. Bibcode:2012A&A...537A.120Z. doi:10.1051/0004-6361/201117691. Vizier catalog entry
  4. Houk, Nancy; Smith-Moore, M. (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.
  5. Mallama, A. (2014). "Sloan Magnitudes for the Brightest Stars". The Journal of the American Association of Variable Star Observers. 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry
  6. Wilson, R. E. (1953). "General Catalogue of Stellar Radial Velocities". Carnegie Institute Washington D.C. Publication. Carnegie Institution for Science. Bibcode:1953GCRV..C......0W. LCCN 54001336.
  7. Tetzlaff, N.; et al. (2011). "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun". Monthly Notices of the Royal Astronomical Society. 410 (1): 190–200. arXiv:1007.4883. Bibcode:2011MNRAS.410..190T. doi:10.1111/j.1365-2966.2010.17434.x. Vizier catalog entry
  8. Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures". Astronomy and Astrophysics. 352: 555–562. arXiv:astro-ph/9911002. Bibcode:1999A&A...352..555A. Vizier catalog entry
  9. David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal. 804 (2): 146. arXiv:1501.03154. Bibcode:2015ApJ...804..146D. doi:10.1088/0004-637X/804/2/146. Vizier catalog entry
  10. Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters. 38 (12): 771–782. arXiv:1606.08814. Bibcode:2012AstL...38..771G. doi:10.1134/S1063773712120031. Vizier catalog entry
  11. "h02 Sgr". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-07-27.
  12. 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. arXiv:0806.2878. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.
  13. Garrison, R. F.; Gray, R. O. (1994). "The late B-type stars: Refined MK classification, confrontation with stromgren photometry, and the effects of rotation". The Astronomical Journal. 107: 1556. Bibcode:1994AJ....107.1556G. doi:10.1086/116967. Garrison has note: "Balmer shell cores?"
  14. Hubrig, S.; et al. (2007). "Establishing the nature of companion candidates to X-ray-emitting late B-type stars". Monthly Notices of the Royal Astronomical Society. 381 (4): 1569. arXiv:0708.0860. Bibcode:2007MNRAS.381.1569H. doi:10.1111/j.1365-2966.2007.12325.x.
  15. Mason, Brian D.; et al. (2001). "The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog". The Astronomical Journal. 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920. Vizier catalog entry
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