Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Lyra |
Right ascension | 18h 19m 51.70908s [1] |
Declination | +36° 03′ 52.3691″ [1] |
Apparent magnitude (V) | 4.33 [2] |
Characteristics | |
Evolutionary stage | giant |
Spectral type | K2-IIIabCN0.5 [3] |
U−B color index | +1.17 [4] |
B−V color index | +1.162±0.013 [2] |
Variable type | suspected [5] |
Astrometry | |
Radial velocity (Rv) | −24.36±0.13 [6] km/s |
Proper motion (μ) |
RA: −16.75
[1]
mas/
yr Dec.: +41.09 [1] mas/ yr |
Parallax (π) | 12.96 ± 0.14 mas [1] |
Distance | 252 ± 3
ly (77.2 ± 0.8 pc) |
Absolute magnitude (MV) | −0.11 [2] |
Details | |
Radius | 18 [6] R☉ |
Luminosity | 127.4 [7] L☉ |
Surface gravity (log g) | 2.51 [8] cgs |
Temperature | 4,638 [8] K |
Metallicity [Fe/H] | +0.13 [8] dex |
Rotational velocity (v sin i) | 5.0 [6] km/s |
Other designations | |
Database references | |
SIMBAD | data |
κ Lyrae, Latinized as Kappa Lyrae, is a solitary [10] star in the northern constellation of Lyra, near the constellation border with Hercules. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 4.33. [2] This object is located approximately 252 light years from the Sun based on parallax, [1] but is moving closer with a radial velocity of −24 km/s. [6]
This is an aging giant star with a stellar classification of K2-IIIabCN0.5, [3] with the suffix notation indicating a mild underabundance of cyanogen. Having exhausted the supply of hydrogen at its core, the star has cooled and expanded. It now has 18 [6] times the Sun's girth and is radiating 127 [7] times the luminosity of the Sun at an effective temperature of 4,638 K. [8] κ Lyrae is a red clump giant, which means it is on the horizontal branch and is generating energy through core helium fusion. [11] It is a suspected small amplitude variable star. [5]