38 Lyncis

38 Lyncis is a multiple star system in the northern constellation of Lynx. It located about 125 light-years from the Sun, based on parallax.

38 Lyncis

Location of 38 Lyncis (circled in red)
Observation data Epoch J2000      Equinox J2000
Constellation	Lynx
Right ascension	09h 18m 50.64384s[1]
Declination	+36° 48′ 09.3331″[1]
Apparent magnitude (V)	3.82[2] (3.95 + ? + 6.30)[3]
Characteristics
Spectral type	A3V[4] (A1V + A4V)[5]
B−V color index	0.066±0.010[2]
Astrometry
Radial velocity (Rv)	4.0±2.7[2] km/s
Absolute magnitude (MV)	+0.98[6]
A
Proper motion (μ)	RA: –36.288[7] mas/yr Dec.: −121.767[7] mas/yr
Parallax (π)	27.8044±0.7879 mas[7]
Distance	117 ± 3 ly (36 ± 1 pc)
B
Proper motion (μ)	RA: –26.513[8] mas/yr Dec.: −127.261[8] mas/yr
Parallax (π)	24.4730±0.1240 mas[8]
Distance	133.3 ± 0.7 ly (40.9 ± 0.2 pc)
Details
38 Lyn A
Mass	1.90[9] M☉
Radius	3.07[10] R☉
Luminosity	32[6] L☉
Surface gravity (log g)	3.86[9] cgs
Temperature	8,862±301[9] K
Metallicity [Fe/H]	−0.36[11] dex
Rotational velocity (v sin i)	163[11] km/s
Age	213[9] Myr
38 Lyn B
Mass	1.30/0.90[12] M☉
Radius	2.55[8] R☉
Luminosity	5[8] L☉
Temperature	5,409[8] K
Other designations
38 Lyn, BD+37°1965, FK5 346, HD 80081, HIP 45688, HR 3690, SAO 61391, WDS J09188+3648[13]
Database references
SIMBAD	data
	A
	B

When viewed through a moderate telescope, two components—a brighter blue-white star of magnitude 3.9 and a fainter star of magnitude 6.1 that has been described as lilac as well as blue-white—can be seen.^[14] The pair have an angular separation of 2.6″ and an estimated period of 429 years.^[12] The fainter component is itself a close binary which can only be resolved using speckle interferometry. The two were separated by 0.06″ in 1993^[15] and 0.237″ in 2008,^[16] and have an estimated orbital period of 2.1 years.^[12] A further faint star, component E 100″ away, is a proper-motion companion.^[17][18] Two other faint companions listed in multiple star catalogues as components C and D are unrelated background objects.^[19][20]

38 Lyncis was given as a standard star for the spectral class of A3 V when the Morgan-Keenan classification system was first defined in 1943, apparently for the two components combined.^[21]

The primary star, component A, is a class A main sequence star around twice the mass of the sun. An effective temperature of 8,862 K and a radius of 3.09 R_☉ mean that it is over thirty times more luminous than the sun. It has been listed as a λ Boötis star, although it is no longer considered to be a member.^[6] The fainter of the pair, component B, has been given a spectral class of A4V, although it consists of two very close stars. Their properties are poorly-known, even the difference in their apparent magnitudes can only be estimated to be approximately 2. Based on this, their masses are estimated to be 1.3 M_☉ and 0.9 M_☉ respectively.^[12] Component E is a 15th magnitude star with an approximate spectral type of M2, a red dwarf, and an estimated mass of 0.31 M_☉,^[12] and a temperature of 3,816 K.^[18]