109 Herculis

109 Herculis
Observation data
Epoch J2000      Equinox J2000
Constellation Hercules
Right ascension 18h 23m 41.88971s[1]
Declination +21° 46′ 11.1096″[1]
Apparent magnitude (V) 3.84[2]
Characteristics
Evolutionary stage horizontal branch[3]
Spectral type K2IIIab[4]
B−V color index 1.168±0.005[5]
Astrometry
Radial velocity (Rv)−57.55±0.27[6] km/s
Proper motion (μ) RA: +195.971 mas/yr[1]
Dec.: −243.234 mas/yr[1]
Parallax (π)26.9636 ± 0.1049 mas[1]
Distance121.0 ± 0.5 ly
(37.1 ± 0.1 pc)
Absolute magnitude (MV)+0.87[7]
Details[8]
Mass1.05±0.18 M☉
Radius11.55+0.20
−0.19 R☉
Luminosity52.4±3 L☉
Surface gravity (log g)2.24 cgs
Temperature4,569±60 K
Metallicity [Fe/H]−0.06 dex
Rotational velocity (v sin i)4.4[6] km/s
Age6.39±2.71 Gyr
Other designations
109 Her, BD+21°3411, FK5 690, HD 169414, HIP 90139, HR 6895, SAO 86003, WDS J18237+2146[9]
Database references
SIMBADdata

109 Herculis is a single[10] star in the northern constellation of Hercules. It is visible to the naked eye as a faint, orange-hued point of light with an apparent visual magnitude of 3.84.[2] The star is located around 121 light-years (37 parsecs) distant, based on parallax.[1] It is moving closer to the Earth with a heliocentric radial velocity of −58 km/s,[6] and may come as close as 81 light-years away in around 328,000 years.[5]

This is an aging giant star with a stellar classification of K2IIIab.[4] It is a red clump giant,[3] meaning it on the horizontal branch and is generating energy through helium fusion at its core. The star is roughly six billion years old with slightly more mass than the Sun.[8] With the supply of hydrogen at its core exhausted, it has expanded to nearly 12 times the Sun's radius.[8] The star is radiating 52 times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,569 K.[8]

This star, together with 93 Her, 95 Her, and 102 Her, were consist Cerberus, the obsolete constellation[11]

  1. ^ a b c d e Cite error: The named reference DR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Ducati2002 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Puzeras2010 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference perkins1989 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Massarotti2008 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Cardini2005 was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference Baines2018 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. ^ Ian Ridpath's Star Tales - Cerberus