Astronomy:Gliese 581e
Size comparison of Gliese 581e with Earth (Based on selected hypothetical modeled compositions)[lower-alpha 1] | |
| Discovery[1] | |
|---|---|
| Discovered by | Mayor et al. |
| Discovery site | La Silla Observatory, Chile |
| Discovery date | 21 April 2009 |
| Radial velocity | |
| Orbital characteristics[3] | |
| 0.02799±0.0003 astronomical unit|AU | |
| Eccentricity | 0.012+0.015 −0.008 |
| Orbital period | 3.1481±0.0004 d |
| Inclination | 47°+15° −13° |
| astron|astron|helion}} | 2454752.33 ± 0.05[2] |
| 226°+91° −55° | |
| Semi-amplitude | 1.8±0.1 m/s |
| Star | Gliese 581 |
| Physical characteristics[3] | |
| Mass | 2.48+0.70 −0.42 M🜨 |
Gliese 581e /ˈɡliːzə/ or Gl 581e 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 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]
With a minimum mass of about 1.9 Earth masses, Gliese 581e was the least massive exoplanet known around a normal star at the time of discovery in 2009, with only PSR B1257+12 A being less massive.[4][5] A 2024 study determined the orbital inclination of the planet, allowing its true mass to be determined, which is about 30% greater than the minimum mass at about 2.5 Earth masses.[3]
Gliese 581e completes an orbit around its parent star in 3.15 days. At an orbital distance of just 0.028 astronomical unit|AU (4,200,000 km) from its parent star, it orbits further in than the habitable zone.[2] 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.[6]
See also
Notes
- ↑ The estimated range of sizes in this image from 2009 is based on the planet's minimum mass. Since the true mass is now known to be somewhat greater, the sizes may be underestimated.
References
- ↑ 1.0 1.1 Mayor, Michel; Bonfils, Xavier; Forveille, Thierry et al. (2009). "The HARPS search for southern extra-solar planets, XVIII. An Earth-mass planet in the GJ 581 planetary system". Astronomy and Astrophysics 507 (1): 487–494. doi:10.1051/0004-6361/200912172. Bibcode: 2009A&A...507..487M. http://obswww.unige.ch/~udry/Gl581_preprint.pdf.
- ↑ 2.0 2.1 Robertson, Paul; Mahadevan, Suvrath; Endl, Michael; Roy, Arpita (3 July 2014). "Stellar activity masquerading as planets in the habitable zone of the M dwarf Gliese 581". Science 345 (6195): 440–444. doi:10.1126/science.1253253. PMID 24993348. Bibcode: 2014Sci...345..440R.
- ↑ 3.0 3.1 3.2 von Stauffenberg, A.; Trifonov, T.; Quirrenbach, A. et al. (2024-06-05). "The CARMENES search for exoplanets around M dwarfs. Revisiting the GJ 581 multi-planetary system with new Doppler measurements from CARMENES, HARPS, and HIRES". Astronomy & Astrophysics. doi:10.1051/0004-6361/202449375. ISSN 0004-6361. Bibcode: 2024A&A...688A.112V.
- ↑ Rincon, Paul; Amos, Jonathan (2009-04-21). "Lightest exoplanet is discovered". BBC. http://news.bbc.co.uk/1/hi/sci/tech/8008683.stm.
- ↑ Overbye, Dennis (April 21, 2009). "Astronomers Find Planet Closer to Size of Earth". New York Times. https://www.nytimes.com/2009/04/22/science/22planet.html.
- ↑ Barnes, Rory; Jackson, Brian; Greenberg, Richard; Raymond, Sean N. (2009-06-09). "Tidal Limits to Planetary Habitability". The Astrophysical Journal 700 (1): L30–L33. doi:10.1088/0004-637X/700/1/L30. Bibcode: 2009ApJ...700L..30B.
External links
- Lightest exoplanet yet discovered European Southern Observatory press release
- Scientists discover a nearly Earth-sized planet
- Publications at Exoplanet.eu
Template:Gliese 581
Coordinates:
15h 19m 26s, −07° 43′ 20″
