Gliese 581b

Gliese 581 b
Size comparison of Gliese 581 b with Neptune
(Based on selected hypothetical modeled compositions)
Discovery
Discovered byX. Bonfils, T. Forveille, X. Delfosse,
S. Udry, M. Mayor, C. Perrier,
F. Bouchy, F. Pepe, D. Queloz,
J.-L. Bertaux
Discovery dateAugust 22, 2005
announced November 30, 2005
Doppler spectroscopy
Orbital characteristics
0.0399±0.0005 AU
Eccentricity0.0342+0.009
−0.010
5.3686±0.0001 d
Inclination47°+15°
−13°
2454751.76 ± 0.01
54°+13°
−14°
Semi-amplitude12.3±0.1 m/s
StarGliese 581
Physical characteristics
Mass20.5+6.2
−3.5
 M🜨

    Gliese 581b or Gl 581b is an exoplanet orbiting within the Gliese 581 system, located 20.5 light-years (6.3 parsecs) away from Earth in the Libra constellation. It is the first planet discovered of three confirmed in the system so far, and the second in order from the star.