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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| 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 mas[1] |
| Distance | 178 ± 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 | |
| Mass | 2 M☉ |
| Radius | 8 R☉ |
| Luminosity | 40 L☉ |
| Surface gravity (log g) | 3.0 cgs |
| Temperature | 5,164±5 K |
| Metallicity [Fe/H] | 0.05 dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
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
edit- ^ a b c d e f van Leeuwen, F.; et al. (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. S2CID 18759600.
- ^ a b 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. Bibcode:2002yCat.2237....0D.
- ^ a b Monks, Neale (2010). Go-To Telescopes Under Suburban Skies. New York, New York: Springer Science & Business Media. p. 58. ISBN 9781441968517.
- ^ a b 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. Bibcode:2012A&A...546A..69M. doi:10.1051/0004-6361/201219774. A69.
- ^ a b Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode:1986EgUBV........0M.
- ^ a b c d 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. Bibcode:2008AJ....135..209M. doi:10.1088/0004-6256/135/1/209. S2CID 121883397.
- ^ a b "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 1 August 2017. Retrieved 30 July 2017.