Kappa Herculis

κ Herculis

Historical view of the Hercules constellation showing Marfik (κ Her) as the hero's left "elbow".
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
κ Her A
Right ascension 16h 08m 04.52481s[1]
Declination 17° 02′ 49.1150″[1]
Apparent magnitude (V) 4.994[2]
κ Her B
Right ascension 16h 08m 04.95406s[3]
Declination 17° 03′ 15.6853″[3]
Apparent magnitude (V) 6.25[4]
Characteristics
Spectral type G7III + K0IV[5]
U−B color index +0.630[citation needed]
B−V color index +0.931[citation needed]
Variable type suspected[6]
Astrometry
κ Her A
Radial velocity (Rv)−10.50[7] km/s
Proper motion (μ) RA: −34.062[8] mas/yr
Dec.: −6.585[8] mas/yr
Parallax (π)8.5601 ± 0.1338 mas[8]
Distance381 ± 6 ly
(117 ± 2 pc)
Absolute magnitude (MV)-45[9]
κ Her B
Radial velocity (Rv)+32.21[10] km/s
Proper motion (μ) RA: −19.465[11] mas/yr
Dec.: −25.142[11] mas/yr
Parallax (π)8.1307 ± 0.0502 mas[11]
Distance401 ± 2 ly
(123.0 ± 0.8 pc)
Details
κ Her A
Mass3.17[12] M☉
Radius16[8] R☉
Luminosity148[9] L☉
Surface gravity (log g)2.90[12] cgs
Temperature5,119[12] K
Metallicity [Fe/H]+0.04[12] dex
Rotational velocity (v sin i)9.9[13] km/s
Age309[9] Myr
κ Her B
Radius11[11] R☉
Luminosity55[11] L☉
Temperature4,750[11] K
Metallicity [Fe/H]+0.131[14] dex
Rotational velocity (v sin i)1.0[13] km/s
Other designations
Marsic, κ Her, 7 Herculis, CCDM J16081+1703, NSV 7471, AAVSO 1603+17, WDS 16081+1703
A: HR 6008, HD 145001, HIP 79043, BD +77°2964
B: HR 6009, HD 145000, HIP 79045, BD +77°2965
Database references
SIMBADκ Her
κ Her A
κ Her B

Kappa Herculis (κ Herculis, abbreviated Kappa Her, κ Her) is an optical double star in the constellation of Hercules. The two components, Kappa Herculis A (Marsic /ˈmɑːrsɪk/, the traditional name of the system)[15] and B, were 27.3 arc seconds apart in 2000. Based on parallax measurements from the Hipparcos mission, κ Her A is about 113 parsecs (370 light-years) from the Sun and κ Her B is 600 parsecs (2,000 light-years); more recent parallax measurements suggest that B is around 5% more distant than A.

A faint third component Kappa Herculis C is just over 1 arc-minute away.[16] It is at the same distance as κ Her A and has an almost-identical space motion.[17]

The star 8 Herculis forms a naked eye pair with Kappa Herculis 14′ away.

  1. ^ a b Cite error: The named reference hipparcosA was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference tycho2 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference hipparcosB was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference ubv was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference mk was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference gcvs was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference pulkovo was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference dr2A was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference takeda was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference coravel was invoked but never defined (see the help page).
  11. ^ a b c d e f Cite error: The named reference dr2B was invoked but never defined (see the help page).
  12. ^ a b c d Cite error: The named reference liu was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference medeiros was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference franchini was invoked but never defined (see the help page).
  15. ^ Davis, George A. (1944). "The pronunciations, derivations, and meanings of a selected list of star names". Popular Astronomy. 52: 8–30. Bibcode:1944PA.....52....8D.
  16. ^ Cite error: The named reference wds was invoked but never defined (see the help page).
  17. ^ Cite error: The named reference dr2C was invoked but never defined (see the help page).