Astronomy:38 Lyncis
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| 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 |
| Distance | 117 ± 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 |
| Distance | 133.3 ± 0.7 ly (40.9 ± 0.2 pc) |
| Details | |
| 38 Lyn A | |
| Mass | 1.90[9] M☉ |
| Radius | 3.07[10] R☉ |
| Luminosity | 32[6] L☉ |
| Surface gravity (log g) | 3.86[9] cgs |
| Temperature | 8,862±301[9] K |
| Metallicity [Fe/H] | −0.36[11] dex |
| Rotational velocity (v sin i) | 163[11] km/s |
| Age | 213[9] Myr |
| 38 Lyn B | |
| Mass | 1.30/0.90[12] M☉ |
| Radius | 2.55[8] R☉ |
| Luminosity | 5[8] L☉ |
| Temperature | 5,409[8] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
| 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
- ↑ 1.0 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. Bibcode: 2007A&A...474..653V.
- ↑ 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. Bibcode: 2012AstL...38..331A.
- ↑ 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. Bibcode: 2008MNRAS.389..869E.
- ↑ 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. Bibcode: 1969AJ.....74..375C.
- ↑ 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. Bibcode: 1968RGOB..135..385P.
- ↑ 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. Bibcode: 2017MNRAS.466..546M.
- ↑ 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. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 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. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 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. Bibcode: 2015ApJ...804..146D.
- ↑ 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. Bibcode: 2016ApJ...826..171G.
- ↑ 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. Bibcode: 2009PASJ...61.1165T.
- ↑ 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.
- ↑ "38 Lyncis". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=38+Lyncis.
- ↑ 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.
- ↑ 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. Bibcode: 1993AJ....106.1639M.
- ↑ 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. Bibcode: 2008AJ....135.1334H.
- ↑ 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. Bibcode: 2014MNRAS.437.1216D.
- ↑ 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. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ Mason, B. D. et al. (2014). "The Washington Visual Double Star Catalog". The Astronomical Journal 122 (6): 3466–3471. doi:10.1086/323920. Bibcode: 2001AJ....122.3466M. http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/wds. Retrieved 2015-07-22.
- ↑ 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. Bibcode: 1995BICDS..46....3D.
- ↑ Morgan, William Wilson; Keenan, Philip Childs; Kellman, Edith (1943). "An atlas of stellar spectra, with an outline of spectral classification". Chicago. Bibcode: 1943assw.book.....M.
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