HD 128311 b

HD 128311 b is an exoplanet^[2] located approximately 54 light-years away in the constellation of Boötes. This planet orbits in an eccentric orbit about 1.084 AU from its star (HD 128311). The planet has a minimum mass of 1.769 Jupiter masses.^[3][1]

HD 128311 b

Discovery
Discovered by	Butler et al.
Discovery site	California, United States
Discovery date	2002
Detection method	Doppler Spectroscopy
Orbital characteristics[1]
Apastron	1.412 AU (211,200,000 km)
Periastron	0.756 AU (113,100,000 km)
Semi-major axis	1.084 ± 0.006 AU (162,160,000 ± 900,000 km)
Eccentricity	0.303±0.011
Orbital period (sidereal)	453.019 ± 0.404 d (1.24030 ± 0.00111 a)
Average orbital speed	26.2
Inclination	>30
Time of periastron	2450198.691±4.472
Argument of periastron	57.864±3.258
Semi-amplitude	55.627±0.456
Star	HD 128311
Physical characteristics[1]
Mass	≥1.769±0.023 MJ