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] |
Distance | 102.8 ± 0.7
ly (31.5 ± 0.2 pc) |
Absolute magnitude (MV) | +1.26 [5] |
Details | |
Mass | 2.9 [3] M☉ |
Radius | 1.8 [6] R☉ |
Luminosity | 29 [3] L☉ |
Surface gravity (log g) | 4.03 [4] cgs |
Temperature | 9,506 [3] K |
Rotational velocity (v sin i) | 220 [7] km/s |
Age | 184+93 −134 [7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
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]