Kappa Lyrae

Kappa Lyrae
Location of κ Lyrae (circled)
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]
Distance252 ± 3 ly
(77.2 ± 0.8 pc)
Absolute magnitude (MV)−0.11[2]
Details
Radius18[6] R☉
Luminosity127.4[7] L☉
Surface gravity (log g)2.51[8] cgs
Temperature4,638[8] K
Metallicity [Fe/H]+0.13[8] dex
Rotational velocity (v sin i)5.0[6] km/s
Other designations
κ Lyr, BD+36°3094, HD 168775, HIP 89826, HR 6872, SAO 66869[9]
Database references
SIMBADdata

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]

  1. ^ a b c d e f Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference MERMILLIOD was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference asp106_700_611 was invoked but never defined (see the help page).
  6. ^ a b c d e Cite error: The named reference aj135_1_209 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Mcdonald_et_al_2012 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference aa554_A84 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Alves2000 was invoked but never defined (see the help page).