V1054 Ophiuchi

V1054 Ophiuchi

An ultraviolet band light curve for a flare on V1054 Ophiuchi, plotted from data published by Dal and Evren (2010)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Ophiuchus
AB
Right ascension 16h 55m 28.75757s
Declination −08° 20 10.7878
Apparent magnitude (V) 9.74/10.34/10.84
Gliese 643
Right ascension 16h 55m 25.22225s
Declination −08° 19 21.2970
Apparent magnitude (V) 11.74
C (VB 8)
Right ascension 16h 55m 35.25574s
Declination −08° 23 40.7531
Apparent magnitude (V) 16.80
Characteristics
AB
Spectral type M3 V / M4 Ve
Gliese 643
Spectral type M3.5 V
C (VB 8)
Spectral type M7.0 V
Astrometry
AB
Radial velocity (Rv)14.89±0.05 km/s
Proper motion (μ) RA: −817.84±6.68 mas/yr
Dec.: −873.53±3.53 mas/yr
Parallax (π)161.41±5.64 mas
Distance20.2 ± 0.7 ly
(6.2 ± 0.2 pc)
Absolute magnitude (MV)10.23
Gliese 643
Radial velocity (Rv)15.20±0.15 km/s
Proper motion (μ) RA: −817.580(52) mas/yr
Dec.: −898.595(40) mas/yr
Parallax (π)153.8754±0.0474 mas
Distance21.196 ± 0.007 ly
(6.499 ± 0.002 pc)
Absolute magnitude (MV)12.60
VB 8
Proper motion (μ) RA: −813.038(63) mas/yr
Dec.: −870.609(44) mas/yr
Parallax (π)153.9659 ± 0.0570 mas
Distance21.184 ± 0.008 ly
(6.495 ± 0.002 pc)
Absolute magnitude (MV)17.75
Orbit
PrimaryV1054 Oph A
CompanionV1054 Oph B
Period (P)1.717267±0.000039 yr
Semi-major axis (a)0.2273±0.0004"
(1.46683 AU)
Eccentricity (e)0.042±0.001
Inclination (i)160.3±0.1°
Longitude of the node (Ω)−10.2±0.2°
Periastron epoch (T)MJD 53943±3
Argument of periastron (ω)
(secondary)
306.0±1.5°
Orbit
PrimaryV1054 Oph Ba
CompanionV1054 Oph Bb
Period (P)2.965509±0.000006 d
Semi-major axis (a)0.00687"
(0.04432 AU)
Eccentricity (e)0.0209±0.0008
Inclination (i)164.18±0.08°
Periastron epoch (T)MJD 50919.48±0.03
Argument of periastron (ω)
(secondary)
150.0±3.0°
Details
AB
Mass0.4155±0.0057 / 0.3466±0.0047 / 0.3143±0.0040 M
Gliese 643
Mass0.19 M
C (VB 8)
Mass0.0914+0.0026
−0.0025
 M
Radius0.1214+0.0060
−0.0057
 R
Luminosity0.000645+0.000004
0.000005
 L
Temperature2,640+65
−64
 K
Rotation11.19±0.02 days
Other designations
CCDM J16555-0820
AB: V1054 Oph, BD−08°4352, GJ 644, HD 152751, HIP 82817, SAO 141439, LHS 428, Wolf 630
GJ 643: GJ 643, HIP 82809, LHS 427, Wolf 629
C: GJ 644 C, LHS 429, VB 8
Database references
SIMBADABab
GJ 643
C (vB 8)

V1054 Ophiuchi, together with the star Gliese 643, is a nearby quintuple star system, located in the constellation Ophiuchus at a distance of 21.2 light-years. It consists of five stars, all of which are red dwarfs. The alternative designation of Wolf 630 forms the namesake of a moving group of stars that share a similar motion through space.