Gliese 649 is a smallstar with an orbitingexoplanet in theconstellationHercules. It has anapparent visual magnitude of 9.7,[3] which is too faint to be seen with the naked eye. The system is located at a distance of 33.9 light years based onparallax, and is drifting further away with aradial velocity of 3.8 km/s.[2]
This is anM-type main-sequence star, ared dwarf, with astellar classification of M1.0V.[3] It has 52% of the mass of the Sun and 53% of the Sun's girth. In the visible light band, the star is radiating 4.4% of the luminosity of the Sun from itsphotosphere at aneffective temperature of 3,621 K.[4] It is spinning slowly with arotation period of 24.9 days.[3]
A Saturn-mass planet was detected around the red dwarf star by J. A. Johnson and associates in 2010.[7] It has aminimum mass 32.8% ofJupiter's mass and is located 1.15astronomical units from its star in eccentric orbit (e=0.3). Assuming a luminosity of 4.5% that of theSun, thehabitable zone is located at0.21 AU, thus the planet should be as cold as if it were located at5.5 AU from a Solar-like star. Also accounting for differentperiastron andapastron positions of 0.8 and1.49 AU respectively, the planet could likely show seasonal temperature changes.
Using results from theHerschel Space Observatory survey of 21 late-type stars carried out in 2010, a debris disk was discovered between approximately 6 and30 AU. The disk was not detected at 22μm by NASA'sWide-field Infrared Survey Explorer so therefore it is likely to be below 100 Kelvin and similar to theKuiper belt. The disk was marginally resolved, appearing very asymmetric, and so is probably consistent with being closer to edge-on, rather than face-on, in its inclination.[8]
| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b | ≥0.258+0.023 −0.022 MJ | 1.112+0.035 −0.037 | 600.1±1.7 | 0.083+0.068 −0.055 | — | — |
| Kuiper belt | ~6–~30AU | ~45-90° | — | |||
