HD 40307 e

HD 40307 e is an extrasolar planet 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]

HD 40307 e
Discovery
Discovered byMikko Tuomi et al.
Discovery siteLa Silla Observatory, Chile
Discovery dateOctober 28, 2012
radial velocity, using HARPS
Orbital characteristics
0.1886 [0.1782, 0.1969] AU
Eccentricity0.06 [0, 0.18][1]
34.62 [34.42, 34.83][1] d
Semi-amplitude0.84 [0.53, 1.16][1]
StarHD 40307

    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.[5] Planets like this in that system have been presumed "super-Earth".[6]

    However planets b, c, and d are presumed to have migrated in from outer orbits; and planet b is predicted a sub-Neptune.[7] 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

    1. Tuomi, Mikko; Anglada-Escude, Guillem; Gerlach, Enrico; Jones, Hugh R. R.; Reiners, Ansgar; Rivera, Eugenio J.; Vogt, Steven S.; Butler, R. Paul (2012). "Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307". Astronomy. 549: A48. arXiv:1211.1617v1. Bibcode:2013A&A...549A..48T. doi:10.1051/0004-6361/201220268.
    2. Wall, Mike (November 7, 2012). "'Super-Earth' Alien Planet May Be Habitable for Life". Space.com. Retrieved November 8, 2012.
    3. Tate, Karl (November 7, 2012). "Super-Earth Planet: Potentially Habitable Alien World Explained (Infographic)". Space.com. Retrieved November 8, 2012.
    4. Murrin, Marc (November 8, 2012). "Astronomers discover a potentially habitable Super-Earth HD 40307g (Infographic)". tech-stew.com. Archived from the original on November 10, 2012. Retrieved November 8, 2012.
    5. Tuomi, Fig. 17
    6. 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.
    7. 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.


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