Astronomy:38 Lyncis

From HandWiki
Short description: Star in the constellation Lynx
38 Lyncis
Lynx constellation map.svg
Red circle.svg
Location of 38 Lyncis (circled in red)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lynx
Right ascension  09h 18m 50.64384s[1]
Declination +36° 48′ 09.3331″[1]
Apparent magnitude (V) 3.82[2] (3.95 + ? + 6.30)[3]
Characteristics
Spectral type A3V[4] (A1V + A4V)[5]
B−V color index 0.066±0.010[2]
Astrometry
Radial velocity (Rv)4.0±2.7[2] km/s
Absolute magnitude (MV)+0.98[6]
A
Proper motion (μ) RA: –36.288[7] mas/yr
Dec.: −121.767[7] mas/yr
Parallax (π)27.8044 ± 0.7879[7] mas
Distance117 ± 3 ly
(36 ± 1 pc)
B
Proper motion (μ) RA: –26.513[8] mas/yr
Dec.: −127.261[8] mas/yr
Parallax (π)24.4730 ± 0.1240[8] mas
Distance133.3 ± 0.7 ly
(40.9 ± 0.2 pc)
Details
38 Lyn A
Mass1.90[9] M
Radius3.07[10] R
Luminosity32[6] L
Surface gravity (log g)3.86[9] cgs
Temperature8,862±301[9] K
Metallicity [Fe/H]−0.36[11] dex
Rotational velocity (v sin i)163[11] km/s
Age213[9] Myr
38 Lyn B
Mass1.30/0.90[12] M
Radius2.55[8] R
Luminosity5[8] L
Temperature5,409[8] K
Other designations
38 Lyn, BD+37°1965, FK5 346, HD 80081, HIP 45688, HR 3690, SAO 61391, WDS J09188+3648[13]
Database references
SIMBADdata
A
B

38 Lyncis is a multiple star system in the northern constellation of Lynx. It located about 125 light-years from the Sun, based on parallax.

When viewed through a moderate telescope, two components—a brighter blue-white star of magnitude 3.9 and a fainter star of magnitude 6.1 that has been described as lilac as well as blue-white—can be seen.[14] The pair have an angular separation of 2.6 and an estimated period of 429 years.[12] The fainter component is itself a close binary which can only be resolved using speckle interferometry. The two were separated by 0.06″ in 1993[15] and 0.237″ in 2008,[16] and have an estimated orbital period of 2.1 years.[12] A further faint star, component E 100 away, is a proper-motion companion.[17][18] Two other faint companions listed in multiple star catalogues as components C and D are unrelated background objects.[19][20]

38 Lyncis was given as a standard star for the spectral class of A3 V when the Morgan-Keenan classification system was first defined in 1943, apparently for the two components combined.[21]

The primary star, component A, is a class A main sequence star around twice the mass of the sun. An effective temperature of 8,862 K and a radius of 3.09 R mean that it is over thirty times more luminous than the sun. It has been listed as a λ Boötis star, although it is no longer considered to be a member.[6] The fainter of the pair, component B, has been given a spectral class of A4V, although it consists of two very close stars. Their properties are poorly-known, even the difference in their apparent magnitudes can only be estimated to be approximately 2. Based on this, their masses are estimated to be 1.3 M and 0.9 M respectively.[12] Component E is a 15th magnitude star with an approximate spectral type of M2, a red dwarf, and an estimated mass of 0.31 M,[12] and a temperature of 3,816 K.[18]

References

  1. 1.0 1.1 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 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  3. 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  4. Cowley, A. et al. (April 1969). "A study of the bright A stars. I. A catalogue of spectral classifications". Astronomical Journal 74: 375–406. doi:10.1086/110819. Bibcode1969AJ.....74..375C. 
  5. Palmer, D. R. et al. (1968). "The radial velocities spectral types and projected rotational velocities of 633 bright northern A stars". Royal Observatory Bulletin 135: 385. Bibcode1968RGOB..135..385P. 
  6. 6.0 6.1 6.2 Murphy, Simon J.; Paunzen, Ernst (2017). "Gaia's view of the λ Boo star puzzle". Monthly Notices of the Royal Astronomical Society 466 (1): 546–555. doi:10.1093/mnras/stw3141. Bibcode2017MNRAS.466..546M. 
  7. 7.0 7.1 7.2 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. 8.0 8.1 8.2 8.3 8.4 8.5 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.
  9. 9.0 9.1 9.2 9.3 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. doi:10.1088/0004-637X/804/2/146. Bibcode2015ApJ...804..146D. 
  10. Gáspár, András; Rieke, George H.; Ballering, Nicholas (2016). "The Correlation Between Metallicity and Debris Disk Mass". The Astrophysical Journal 826 (2): 171. doi:10.3847/0004-637X/826/2/171. Bibcode2016ApJ...826..171G. 
  11. 11.0 11.1 Takeda, Yoichi; Kang, Dong-Il; Han, Inwoo; Lee, Byeong-Cheol; Kim, Kang-Min (2009). "Can Sodium Abundances of A-Type Stars be Reliably Determined from Na I 5890/5896 Lines?". Publications of the Astronomical Society of Japan 61 (5): 1165–1178. doi:10.1093/pasj/61.5.1165. Bibcode2009PASJ...61.1165T. 
  12. 12.0 12.1 12.2 12.3 12.4 "Multiple Star Catalog". http://www.ctio.noao.edu/~atokovin/stars/stars.php?cat=HR&number=3690. 
  13. "38 Lyncis". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=38+Lyncis. 
  14. Monks, Neale (2010). Go-To Telescopes Under Suburban Skies. New York, New York: Springer Science & Business Media. p. 58. ISBN 9781441968517. https://books.google.com/books?id=waO6tUtfblsC&pg=PA58. 
  15. McAlister, Harold A.; Mason, Brian D.; Hartkopf, William I.; Shara, Michael M. (1993). "ICCD speckle observations of binary stars. X - A further survey for duplicity among the bright stars". The Astronomical Journal 106: 1639. doi:10.1086/116753. Bibcode1993AJ....106.1639M. 
  16. Hartkopf, William I.; Mason, Brian D.; Rafferty, Theodore J. (2008). "Speckle Interferometry at the Usno Flagstaff Station: Observations Obtained in 2003-2004 and 17 New Orbits". The Astronomical Journal 135 (4): 1334–1342. doi:10.1088/0004-6256/135/4/1334. Bibcode2008AJ....135.1334H. 
  17. De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I. et al. (2014). "The VAST Survey – III. The multiplicity of A-type stars within 75 pc". Monthly Notices of the Royal Astronomical Society 437 (2): 1216–1240. doi:10.1093/mnras/stt1932. Bibcode2014MNRAS.437.1216D. 
  18. 18.0 18.1 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.
  19. Mason, B. D. et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal 122 (6): 3466–3471. doi:10.1086/323920. Bibcode2001AJ....122.3466M. http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds. Retrieved 2015-07-22. 
  20. Dommanget, J.; Nys, O. (1995). "Catalogue of the components of double and multiple stars (CCDM)- First edition, June 1994". Bulletin d'Information du Centre de Données Stellaires 46: 3. Bibcode1995BICDS..46....3D. 
  21. Morgan, William Wilson; Keenan, Philip Childs; Kellman, Edith (1943). "An atlas of stellar spectra, with an outline of spectral classification". Chicago. Bibcode1943assw.book.....M.