HD 40307 e
HD 40307 e is an extrasolar planet candidate suspected to be orbiting the star HD 40307. It is located 42 light-years away in the direction of the southern constellation Pictor. The planet was discovered by the radial velocity method, using the European Southern Observatory's HARPS apparatus[1][2][3] by a team of astronomers led by Mikko Tuomi at the University of Hertfordshire and Guillem Anglada-Escude of the University of Göttingen, Germany.[4]
| Discovery | |
|---|---|
| Discovered by | Mikko Tuomi et al. |
| Discovery site | La Silla Observatory, Chile |
| Discovery date | October 28, 2012 |
| radial velocity, using HARPS | |
| Orbital characteristics | |
| 0.1886 [0.1782, 0.1969] AU | |
| Eccentricity | 0.06 [0, 0.18][1] |
| 34.62 [34.42, 34.83][1] d | |
| Semi-amplitude | 0.84 [0.53, 1.16][1] |
| Star | HD 40307 |
The existence of the planet was disputed in 2015, as more Doppler spectroscopy data has become available.[5]
Planetary characteristics
Its minimum mass is 3.5 that of Earth - the smallest - and dynamical models suggest it cannot be much more (and so is measured close to edge-on).[1] It further gets roughly the same insolation from its star as Mercury gets from the Sun.[6] Planets like this in that system have been presumed "super-Earth".[7]
However planets b, c, and d are presumed to have migrated in from outer orbits; and planet b is predicted a sub-Neptune.[8] It is likely that this planet formed even further out. Whether it is a sub-Neptune, a super-Venus or even a super-Mercury is unknown.
References
- ^ a b c d e Tuomi, Mikko; Anglada-Escudé, Guillem; Gerlach, Enrico; Jones, Hugh R. A.; Reiners, Ansgar; Rivera, Eugenio J.; Vogt, Steven S.; Butler, R. Paul (17 December 2012). "Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307". Astronomy & Astrophysics. 549: A48. arXiv:1211.1617. Bibcode:2013A&A...549A..48T. doi:10.1051/0004-6361/201220268. S2CID 7424216.
- ^ Wall, Mike (November 7, 2012). "'Super-Earth' Alien Planet May Be Habitable for Life". Space.com. Retrieved November 8, 2012.
- ^ Tate, Karl (November 7, 2012). "Super-Earth Planet: Potentially Habitable Alien World Explained (Infographic)". Space.com. Retrieved November 8, 2012.
- ^ Murrin, Marc (November 8, 2012). . tech-stew.com. Archived from the original on November 10, 2012. Retrieved November 8, 2012.
- ^ Díaz, R. F.; et al. (2016). "The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles". Astronomy and Astrophysics. 585. A134. arXiv:1510.06446. Bibcode:2016A&A...585A.134D. doi:10.1051/0004-6361/201526729. S2CID 118531921.
- ^ Tuomi, Fig. 17
- ^ M. Mayor; S. Udry; C. Lovis; F. Pepe; D. Queloz; W. Benz; J.-L. Bertaux; F. Bouchy; C. Mordasini; D. Segransan (2009). "The HARPS search for southern extra-solar planets. XIII. A planetary system with 3 Super-Earths (4.2, 6.9, & 9.2 Earth masses)". Astronomy and Astrophysics. 493 (2): 639–644. arXiv:0806.4587. Bibcode:2009A&A...493..639M. doi:10.1051/0004-6361:200810451. S2CID 116365802.
- ^ Barnes, R.; Jackson, B.; Raymond, S.; West, A.; Greenberg, R. (2009). "The HD 40307 Planetary System: Super-Earths or Mini-Neptunes?". The Astrophysical Journal. 695 (2): 1006–1011. arXiv:0901.1698. Bibcode:2009ApJ...695.1006B. doi:10.1088/0004-637X/695/2/1006. S2CID 18849636.
External links
- . Exoplanets. 2017-05-10. Archived from the original on 2012-11-28. Retrieved 2012-11-10.