Gamma Ophiuchi

γ Ophiuchi
Location of γ Ophiuchi (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ophiuchus
Right ascension 17h 47m 53.55973s[1]
Declination +02° 42′ 26.2000″[1]
Apparent magnitude (V) +3.753[2]
Characteristics
Spectral type A0 V[3] or A1VnkA0mA0[4]
U−B color index +0.040[2]
B−V color index +0.033[2]
Astrometry
Radial velocity (Rv)−7.6±0.3[5] km/s
Proper motion (μ) RA: −24.64[1] mas/yr
Dec.: −74.42[1] mas/yr
Parallax (π)31.73 ± 0.21 mas[1]
Distance102.8 ± 0.7 ly
(31.5 ± 0.2 pc)
Absolute magnitude (MV)+1.26[5]
Details
Mass2.9[3] M☉
Radius1.8[6] R☉
Luminosity29[3] L☉
Surface gravity (log g)4.03[4] cgs
Temperature9,506[3] K
Rotational velocity (v sin i)220[7] km/s
Age184+93
−134[7] Myr
Other designations
Muliphen[8], γ Oph, 62 Ophiuchi, BD+19° 3564, FK5 668, GC 24162, HD 161868, HIP 87108, HR 6629, SAO 122754[9]
Database references
SIMBADdata

Gamma Ophiuchi, Latinized from γ Ophiuchi, is a fourth-magnitude star in the constellation Ophiuchus. Together with Beta Ophiuchi, it forms the serpent-holder's right shoulder.[10] The staris visible to the naked eye with an apparent visual magnitude of +3.75.[2] Based upon an annual parallax shift of 31.73 mas as seen from Earth, it is located 103 light years from the Sun. It is moving closer to the Sun with a radial velocity of −7.6 km/s.[5]

It is known also as Muliphen,[8][11] although at least two more stars are known with this name: Gamma Canis Majoris (often spelled as Muliphein) and Gamma Centauri (often spelled as Muhlifain).[11]

This is an A-type main sequence star with a stellar classification of A0 V.[3] Gray et al. (2003) lists a classification of A1VnkA0mA0,[4] indicating it is of type A1 V with the calcium K-line and metallic lines of an A0 star. It is approximately 184[7] million years old and is spinning rapidly with a projected rotational velocity of 220 km/s.[7] Gamma Ophiuchi has nearly three times the mass of the Sun and 1.8 times the Sun's radius.[6] The star shines with 29[3] times the luminosity of the Sun, which is being emitted from its outer atmosphere at an effective temperature of 9506 K.[3] It is radiating an excess emission of infrared, suggesting the presence of a circumstellar disk of dust at an orbital radius of 64 AU from the host star.[3]

  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 Cite error: The named reference Cousins1984 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference apj663_1_365 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference aass85_3_1015 was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference apj546_1_352 was invoked but never defined (see the help page).
  8. ^ a b Hinckley Allen, Richard. "LacusCurtius • Allen's Star Names — Ophiuchus". Retrieved 2017-01-03.
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Ridpath2018 was invoked but never defined (see the help page).
  11. ^ a b Kaler, Jim. "Muliphen". Retrieved 2017-01-03.