Alpha Lyncis

Alpha Lyncis (α Lyn, α Lyncis) is the brightest star in the northern constellation of Lynx with an apparent magnitude of +3.13.^[4] Unusually, it is the only star in the constellation that has a Bayer designation.^[10] Based upon parallax measurements, this star is located about 220 light-years (67 parsecs) from the Earth.^[1]

α Lyncis

Location of α Lyncis (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Lynx
Right ascension	09h 21m 03.30021s[1]
Declination	+34° 23′ 33.2134″[1]
Apparent magnitude (V)	+3.14[2]
Characteristics
Evolutionary stage	Giant star
Spectral type	K7 III[3]
U−B color index	+1.95[4]
B−V color index	+1.55[4]
Astrometry
Radial velocity (Rv)	37.15[5] km/s
Proper motion (μ)	RA: −218.723 mas/yr[1] Dec.: 16.555 mas/yr[1]
Parallax (π)	14.7±0.18 mas[1]
Distance	220.7+2.9 −2.6 ly (67.7+0.9 −0.8 pc)[6]
Absolute bolometric magnitude (Mbol)	–2.32 ± 0.13[7]
Details
Mass	1.52±0.077[8] M☉
Radius	58.15+0.73 −0.75[9] R☉
Luminosity	621.1±15.8[8] L☉
Surface gravity (log g)	1.06±0.04[8] cgs
Temperature	3,881±20[8] K
Metallicity [Fe/H]	−0.26±0.05[8] dex
Rotational velocity (v sin i)	6.4[5] km/s
Age	1.4[10] Gyr
Other designations
40 Lyncis, HR 3705, HD 80493, BD +35 1979, HIP 45860, SAO 61414, FK5 352, NSV 4456, GC 12880.[11]
Database references
SIMBAD	data

Characteristics

This is a red giant star that has exhausted the hydrogen at its core and has evolved away from the main sequence. It has expanded to about 58 times the Sun's radius^[9] and it is emitting roughly 621 times the luminosity of the Sun. The estimated effective temperature of the star's outer envelope is 3,881 K,^[8] which is lower than the Sun's effective temperature of 5,778 K, and is giving Alpha Lyncis a red-orange hue that is characteristic of late K-type stars.^[12]

Alpha Lyncis is a suspected small-amplitude red variable star^[13] that changes apparent magnitude from +3.17 up to +3.12.^[14] This variability pattern typically occurs in stars that have developed an inert carbon core surrounded by a helium-fusing shell, and suggests that Alpha Lyncis is starting to evolve into a Mira variable.^[10]