Epsilon Eridani b
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| Extrasolar planet | List of extrasolar planets | |
|---|---|---|
 orbiting its parent sun |
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| Parent star | ||
| Star | Epsilon Eridani | |
| Constellation | Eridanus | |
| Right ascension | (α) | 03h 32m 55.8442s |
| Declination | (δ) | −09° 27′ 29.744″ |
| Apparent magnitude | (mV) | 3.73 |
| Distance | 10.5 ± 0.03 ly (3.218 ± 0.009 pc) |
|
| Spectral type | K2V | |
| Orbital elements | ||
| Semimajor axis | (a) | ~3.4 AU |
| Orbital period | (P) | ~2500 d |
| Physical characteristics | ||
| Mass | (m) | ~1.56 MJ |
| Discovery information | ||
| Discovery date | 7 August 2000 | |
| Discoverer(s) | Hatzes et al. | |
| Detection method | Doppler spectroscopy | |
| Discovery site |  United States |
|
| Discovery status | Unconfirmed | |
| Other designations | ||
|
18 Eridani b, Gliese 144 b, HD 22049 b, HIP 16537 b, HR 1084 b
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| Database references | ||
| Extrasolar Planets Encyclopaedia |
data | |
| SIMBAD | data | |
Epsilon Eridani b is an unconfirmed extrasolar planet approximately 10 light-years away orbiting the star Epsilon Eridani, in the constellation of Eridanus (the River).
Contents |
[edit] Discovery
The planet's existence was suspected by a Canadian team led by Bruce Campbell and Gordon Walker in the early 1990s, but their observations were not definitive enough to make a solid discovery. Its formal discovery was announced on August 7, 2000 by a team led by Artie Hatzes. The discoverers gave its mass as 1.2 ± 0.33 times that of Jupiter, with a mean distance of 3.4 AU from the star.[1] Observers, including Geoffrey Marcy, suggested that more information on the star's Doppler noise behaviour created by its large and varying magnetic field was needed before the planet could be confirmed.[2] Astrometric measurements made with the Hubble Space Telescope also suggest the existence of the planet.[3] These observations indicated that the planet has a mass 1.5 times that of Jupiter and shares the same plane as the outer dust disk observed around the star.[4] However, the derived orbit from these measurements is highly eccentric. This is inconsistent with the presence of an asteroid belt at roughly 3 AU from the star, discovered using observations by the Spitzer Space Telescope: the planet would pass through the asteroid belt and rapidly clear it of material.[5] If a giant planet does exist around Epsilon Eridani with a period similar to the one suggested by the radial velocity observations, its orbit must be nearly circular to avoid disrupting the asteroid belt.[6]
[edit] See also
[edit] References
- ^ Hatzes, Artie P.; Cochran, William D.; McArthur, Barbara; Baliunas, Sallie L.; Walker, Gordon A. H.; Campbell, Bruce; Irwin, Alan W.; Yang, Stephenson; Kürster, Martin; Endl, Michael; Els, Sebastian; Butler, R. Paul; Marcy, Geoffrey W. (2000). "Evidence for a Long-Period Planet Orbiting ε Eridani". The Astrophysical Journal 544 (2): L145–L148. arXiv:astro-ph/0009423. Bibcode 2000ApJ...544L.145H. doi:10.1086/317319.
- ^ Marcy,, Geoffrey W.; et al (August 7-11, 2000). "Planetary Messages in the Doppler Residuals (Invited Review)". In A. Penny. Planetary Systems in the Universe, Proceedings of IAU Symposium #202. Manchester, United Kingdom. p. 20–28. Bibcode 2004IAUS..202...20M.
- ^ "Hubble Zeroes in on Nearest Known Exoplanet". Hubble News Desk. 2006-10-09. http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/32/text/. Retrieved 2006-10-10.
- ^ Benedict et al.; McArthur, Barbara E.; Gatewood, George; Nelan, Edmund; Cochran, William D.; Hatzes, Artie; Endl, Michael; Wittenmyer, Robert et al (2006). "The Extrasolar Planet ε Eridani b: Orbit and Mass". The Astronomical Journal 132 (5): 2206–2218. arXiv:astro-ph/0610247. Bibcode 2006AJ....132.2206B. doi:10.1086/508323. http://www.iop.org/EJ/article/1538-3881/132/5/2206/205218.html. Retrieved 2008-11-16.
- ^ Backman, D.; Marengo, M.; Stapelfeldt, K.; Su, K.; Wilner, D.; Dowell, C. D.; Watson, D.; Stansberry, J.; Rieke, G.; Megeath, T.; Fazio, G.; Werner, M. (2009). "Epsilon Eridani's Planetary Debris Disk: Structure and Dynamics Based on Spitzer and Caltech Submillimeter Observatory Observations". The Astrophysical Journal 690 (2): 1522–1538. Bibcode 2009ApJ...690.1522B. doi:10.1088/0004-637X/690/2/1522.
- ^ Brogi, M.; Marzari, F.; Paolicchi, P. (2009). "Dynamical stability of the inner belt around Epsilon Eridani". Astronomy and Astrophysics 499 (2): L13–L16. Bibcode 2009A&A...499L..13B. doi:10.1051/0004-6361/200811609.
[edit] External links
- "Epsilon Eridani b". Extrasolar Visions. http://www.extrasolar.net/planettour.asp?StarCatID=normal&PlanetID=138. Retrieved 2008-06-12.
Coordinates: 
03h 32m 55.8442s, +09° 27′ 29.744″
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