15 Lyncis
Star in the constellation Lynx
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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 | |
| 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 | |
| 15 Lyn, BD+58°982, HD 50522, HIP 33449, HR 2560, SAO 26051 | |
| 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]