1 Lacertae

1 Lacertae is a solitary^[9] star in the northern constellation of Lacerta. It is visible to the naked eye with an apparent visual magnitude of 4.15. Based upon measurements by the Hipparcos spacecraft, this star is located at a distance of roughly 680 light years. It is moving closer to the Earth with a heliocentric radial velocity of −8.6 km/s.

1 Lacertae

Location of 1 Lacertae (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Lacerta
Right ascension	22h 15m 58.17690s[1]
Declination	+37° 44′ 55.4468″[1]
Apparent magnitude (V)	4.15[2]
Characteristics
Spectral type	K3 II-III[3]
U−B color index	+1.70[2]
B−V color index	+1.43[2]
Astrometry
Radial velocity (Rv)	−8.58[4] km/s
Proper motion (μ)	RA: +8.851[1] mas/yr Dec.: –0.089[1] mas/yr
Parallax (π)	4.8108±0.1322 mas[1]
Distance	680 ± 20 ly (208 ± 6 pc)
Absolute magnitude (MV)	−2.61+0.27 −0.24[5]
Details[6]
Mass	4.16±0.28 M☉
Radius	69.01+3.32 −3.07 R☉
Luminosity	1,453±147 L☉
Surface gravity (log g)	2.15 cgs
Temperature	4,288±62 K
Metallicity [Fe/H]	−0.01 dex
Rotational velocity (v sin i)	10[7] km/s
Age	170±30 Myr
Other designations
1 Lac, NSV 25864, BD+37°4526, HD 211388, HIP 109937, HR 8498, SAO 72191[8]
Database references
SIMBAD	data

1 Lacertae in optical light

A stellar classification of K3 II-III^[3] suggests this is an evolved giant star/bright giant hybrid. It is 170 million years old with around four times the mass of the Sun and has expanded to an estimated 69 times the Sun's radius. The star is radiating 1,453 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,288 K, giving it the orange-hued glow of a K-type star.^[10] The star was once a suspected variable, but this was later rescinded.^[11]