Global InformationGliese 581e information
 Size comparison of Gliese 581e with Earth (Based on selected hypothetical modeled compositions) | |
| Discovery[1] | |
|---|---|
| Discovered by | Mayor et al. |
| Discovery site | La Silla Observatory, Chile |
| Discovery date | 21 April 2009 |
Detection method | Radial velocity |
| Orbital characteristics[2] | |
Semi-major axis | 0.029±0.001 AU |
| Eccentricity | 0.125+0.078 −0.015 |
Orbital period (sidereal) | 3.153+0.001 −0.006 d |
Time of periastron | 2454752.33 ± 0.05[3] |
Argument of periastron | 77.4°+23.0° −43.6° |
| Semi-amplitude | 1.55+0.22 −0.13 m/s |
| Star | Gliese 581 |
| Physical characteristics[2] | |
Mean radius | 1.17 R🜨 (estimate) [4] |
| Mass | ≥1.657+0.240 −0.161 M🜨 |
Gliese 581e /ˈɡliːzə/ or Gl 581e is an exoplanet orbiting within the Gliese 581 system, located approximately 20.4 light-years away from Earth in the Libra constellation. It is the third planet discovered in the system (fourth if the disputed planet candidate Gliese 581d is included) and the first in order from the star.
The planet was discovered by an Observatory of Geneva team led by Michel Mayor, using the HARPS instrument on the European Southern Observatory 3.6 m (140 in) telescope in La Silla, Chile. The discovery was announced on 21 April 2009. Mayor's team employed the radial velocity technique, in which the orbit size and mass of a planet are determined based on the small perturbations it induces in its parent star's orbit via gravity.[1]
At a minimum mass of 1.7 Earth masses,[3] it is relatively close in mass to Earth. At an orbital distance of just 0.03 AU (4,500,000 km) from its parent star, however, it orbits further in than the habitable zone. It is unlikely to possess an atmosphere due to its high temperature and strong radiation from the star. Although scientists think it probably has a rocky surface similar to Earth, it is also likely to experience intense tidal heating similar to (and likely more intense than) that affecting Jupiter's moon Io.[5] Gliese 581e completes an orbit around its parent star in approximately 3.15 days.[1][6][7]
- ^ a b c Cite error: The named reference
mayorwas invoked but never defined (see the help page). - ^ a b Cite error: The named reference
Trifonov2018was invoked but never defined (see the help page). - ^ a b Cite error: The named reference
robertson2014was invoked but never defined (see the help page). - ^ "GJ 581 e". NASA Exoplanet Catalog. Retrieved January 18, 2024.
- ^ Barnes, Rory; Jackson, Brian; Greenberg, Richard; Raymond, Sean N. (2009-06-09). "Tidal Limits to Planetary Habitability". The Astrophysical Journal. 700 (1): L30–L33. arXiv:0906.1785. Bibcode:2009ApJ...700L..30B. doi:10.1088/0004-637X/700/1/L30. S2CID 16695095.
- ^ Rincon, Paul; Amos, Jonathan (2009-04-21). "Lightest exoplanet is discovered". BBC. Retrieved 2009-04-21.
- ^ Overbye, Dennis (April 21, 2009). "Astronomers Find Planet Closer to Size of Earth". New York Times.