15 Lyncis is a

binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in wh ...

system in the northern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

Lynx A lynx is a type of wild cat. Lynx may also refer to: Astronomy * Lynx (constellation) * Lynx (Chinese astronomy) * Lynx X-ray Observatory, a NASA-funded mission concept for a next-generation X-ray space observatory Places Canada * Lynx, Ontar ...

. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of 4.35. Based on the system's

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby objects ...

, it is located 178 light-years (54.7 parsecs) away. The pair are moving away from the Earth with a heliocentric

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

of +2 km/s. A telescope reveals it is formed by two yellowish stars of magnitudes 4.7 and 5.8 that are 0.9 arcseconds apart. The two stars orbit each other every 262 years and the

orbital eccentricity In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values betwee ...

is 0.74. The components are a magnitude 4.7

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...

giant star of spectral type G8III, and a magnitude 5.8 F-type main-sequence star of spectral type F8V. 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 The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...

at an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 5,164 K.

References

{{DEFAULTSORT:15 Lyncis G-type giants F-type main-sequence stars Binary stars Lynx (constellation) Durchmusterung objects Lyncis, 15 050522 033449 2560