69 Herculis

This article is about e Herculis. Not to be confused with ε (epsilon) Herculis.
69 Herculis
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 17h 17m 40.25427s[1]
Declination +37° 17′ 29.3995″[1]
Apparent magnitude (V) 4.63 (4.66 + 8.68)[2]
Characteristics
Evolutionary stage main sequence
Spectral type A2V[3]
B−V color index 0.043±0.003[4]
Astrometry
Radial velocity (Rv)−9.90±1.78[5] km/s
Proper motion (μ) RA: −43.05[1] mas/yr
Dec.: +64.36[1] mas/yr
Parallax (π)18.59 ± 0.33 mas[1]
Distance175 ± 3 ly
(53.8 ± 1.0 pc)
Absolute magnitude (MV)0.99[4]
Details
69 Her A
Mass2.12[6] M☉
Radius2.2[7] R☉
Luminosity36.64[4] L☉
Surface gravity (log g)4.02[8] cgs
Temperature9,141[8] K
Metallicity [Fe/H]0.29[8] dex
Rotational velocity (v sin i)141[8] km/s
Age155[9] Myr
Other designations
e Her, 69 Her, BD+37°2864, HD 156729, HIP 84606, HR 6436, SAO 65921[10]
Database references
SIMBADdata

69 Herculis is a binary star[2] system in the northern constellation Hercules. It has the Bayer designation e Herculis, while 69 Herculis is the Flamsteed designation. This object is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of 4.63.[2] The distance to this system can be estimated from parallax measurements, which yields a range of 175 light years. It is moving closer to the Earth with a heliocentric radial velocity of −10 km/s.[5]

The magnitude 4.66[2] primary, designated component A, is an A-type main-sequence star with a stellar classification of A2V.[3] It is 155[9] million years old with 2.12[6] times the mass of the Sun. The star is spinning with a projected rotational velocity of 155 km/s, which is creating an equatorial bulge that is 5% larger than the star's polar radius.[9] It is about 2.2[7] times the size of the Sun and is radiating 37[4] times the Sun's luminosity from its photosphere at an effective temperature of 9,141 K.[8]

The secondary, component B, is magnitude 8.68 star with an angular separation of 0.840″ from the primary, as of 2008.[2] X-ray emission has been detected from this system. As A-type stars are not expected to be X-ray sources, this emission is most likely coming from the companion.[11]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Cowley1969 was invoked but never defined (see the help page).
  4. ^ a b c d Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference David2015 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference cadars was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference Erspamer2003 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference vanBelle2012 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Schröder2007 was invoked but never defined (see the help page).