Epsilon Eridani b
Extrasolar planet | List of extrasolar planets | |
---|---|---|
orbiting its parent sun | ||
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. | |
Discovery 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 | ||
Database references | ||
Extrasolar Planets Encyclopaedia | data | |
SIMBAD | data | |
Exoplanet Archive | data | |
Open Exoplanet Catalogue | 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).
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]
In 2006, the Hubble Space Telescope made Astrometric measurements and confirmed 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] The derived orbit from these measurements is eccentric: either 0.25[4] or 0.7.[5]
Meanwhile the Spitzer Space Telescope detected an asteroid belt at roughly 3 AU from the star.[6] In 2009 Brogi's team claimed that the proposed planet's eccentricity and this belt were inconsistent: the planet would pass through the asteroid belt and rapidly clear it of material.[7]
The planet and the inner belt may be reconciled if that belt's material had migrated in from the outer comet belt (also known to exist).[8]
See also
References
- ↑ Hatzes, Artie P. et al. (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. Retrieved 2006-10-10.
- ↑ 4.0 4.1 Benedict 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. Retrieved 2008-11-16.
- ↑ Butler et al. (2006). "Catalog of Nearby Exoplanets". The Astrophysical Journal 646: 505. Bibcode:2006ApJ...646..505B. doi:10.1086/504701.
- ↑ Backman, D. et al. (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. arXiv:0810.4564. Bibcode:2009ApJ...690.1522B. doi:10.1088/0004-637X/690/2/1522.
- ↑ Brogi, M. et al. (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.
- ↑ Martin Reidemeister et al. (2010). "The cold origin of the warm dust around epsilon Eridani". Astronomy & Astrophysics 527: A57. arXiv:1011.4882. Bibcode:2011A&A...527A..57R. doi:10.1051/0004-6361/201015328.
External links
Coordinates: 03h 32m 55.8442s, −09° 27′ 29.744″