Astronomy:15 Lyncis

From HandWiki
Short description: Star in the constellation Lynx
15 Lyncis
Observation data
Equinox J2000.0]] (ICRS)
Constellation Lynx
Right ascension  06h 57m 16.60526s[1]
Declination +58° 25′ 21.9404″[1]
Apparent magnitude (V) 4.35[2] (4.7 / 5.8)[3]
Characteristics
Spectral type G8III + F8V[4]
U−B color index +0.51[5]
B−V color index +0.85[5]
Astrometry
Radial velocity (Rv)1.86±0.28[6] km/s
Proper motion (μ) RA: 6.08[1] mas/yr
Dec.: -122.83[1] mas/yr
Parallax (π)18.29 ± 0.25[1] mas
Distance178 ± 2 ly
(54.7 ± 0.7 pc)
Orbit[7]
Period (P)262.0 yr
Semi-major axis (a)1.19″
Eccentricity (e)0.74
Inclination (i)78.0°
Longitude of the node (Ω)43.4°
Periastron epoch (T)B 1992.68
Argument of periastron (ω)
(secondary)
98.0°
Details[6]
15 Lyn A
MassM
RadiusR
Luminosity40 L
Surface gravity (log g)3.0 cgs
Temperature5,164±5 K
Metallicity [Fe/H]0.05 dex
Other designations
Database references
SIMBADdata

15 Lyncis is a binary star system in the northern constellation of Lynx. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.35.[2] Based on the system's parallax, it is located 178 light-years (54.7 parsecs) away.[1] The pair are moving away from the Earth with a heliocentric radial velocity of +2 km/s.[6]

A telescope reveals it is formed by two yellowish stars of magnitudes 4.7 and 5.8 that are 0.9 arcseconds apart.[3] The two stars orbit each other every 262 years and the orbital eccentricity is 0.74.[7] The components are a magnitude 4.7 evolved giant star of spectral type G8III, and a magnitude 5.8 F-type main-sequence star of spectral type F8V.[4] The former has exhausted the hydrogen at its core, causing it to expand to 8 times the Sun's radius. It is radiating 40 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 5,164 K.[6]

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. http://www.aanda.org/index.php?option=com_article&access=bibcode&Itemid=129&bibcode=2007A%2526A...474..653VFUL. 
  2. 2.0 2.1 Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues 2237. Bibcode2002yCat.2237....0D. 
  3. 3.0 3.1 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. 
  4. 4.0 4.1 Malkov, O. Yu.; Tamazian, V. S.; Docobo, J. A.; Chulkov, D. A. (2012). "Dynamical Masses of a Selected Sample of Orbital Binaries". Astronomy and Astrophysics 546: 5. doi:10.1051/0004-6361/201219774. A69. Bibcode2012A&A...546A..69M. 
  5. 5.0 5.1 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode1986EgUBV........0M. 
  6. 6.0 6.1 6.2 6.3 Massarotti, Alessandro; Latham, David W.; Stefanik, Robert P.; Fogel, Jeffrey (2008). "Rotational and Radial Velocities for a Sample of 761 Hipparcos Giants and the Role of Binarity". The Astronomical Journal 135 (1): 209–231. doi:10.1088/0004-6256/135/1/209. Bibcode2008AJ....135..209M. 
  7. 7.0 7.1 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6. Retrieved 30 July 2017.