| 词条 | HD 40307 g |
| 释义 |
| name = HD 40307 g | discoverer = Mikko Tuomi et al. | discovery_site = La Silla Observatory, Chile | discovered = October 28, 2012 | discovery_method = radial velocity, using HARPS | apsis = astron | semimajor = {{convert|0.600|AU|km|abbr=on}} | eccentricity = 0.22[1] | period = 197.8 ± 9.0[1] d | semi-amplitude = 0.95 ± 0.3[1] | star = HD 40307 | mean_radius = 2.39 [1] {{Earth radius|link=y}} | mass = 7.09[2] {{Earth mass|link=y}} | single_temperature = 277.6{{citation needed|date=June 2014}}[3] }}HD 40307 g is an exoplanet orbiting in the habitable zone of 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[4][5][6] by a team of astronomers led by Mikko Tuomi at the University of Hertfordshire and Guillem Anglada-Escude of the University of Goettingen, Germany.[7] Composition theoriesThe codiscoverer Hugh Jones, of the University of Hertfordshire in England, surmised: "The longer orbit of the new planet means that its climate and atmosphere may be just right to support life." [5] However, another astronomer, Rory Barnes of the University of Washington, had already studied the orbits of the planets b, c, and d. First, Barnes had presumed b to take on too much tidal heating for it to be terrestrial, instead predicting a "mini-Neptune". He thought that b, c, and d had all migrated inward,[8] which extrapolates to e and f as well, which are further out, but not by much. It is possible that HD 40307 g has also migrated into where it is now. The discoverers of HD 40307 g did not try to refute Barnes, on the nature of b and its extrapolation to the other planets. The composition of g is unsettled.[9] Lead author Mikko Tuomi, also of the University of Hertfordshire, stated "If I had to guess, I would say 50-50 ... But the truth at the moment is that we simply do not know whether the planet is a large Earth or a small, warm Neptune without a solid surface."[5] See also
References1. ^PHL's Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo 2. ^PHL's Exoplanets Catalog - Planetary Habitability Laboratory @ UPR Arecibo 3. ^{{cite web |title=HEC: Data of Potential Habitable Worlds |url=http://phl.upr.edu/projects/habitable-exoplanets-catalog/data |date=November 12, 2012 |publisher=University of Puerto Rico at Arecibo (Planetary Habitability Laboratory)}} 4. ^1 2 3 {{cite journal |last=Tuomi |last2=Anglada-Escude |last3=Gerlach |last4=Jones |last5=Reiners |last6=Rivera |last7=Vogt |last8=Butler |first=Mikko |first2=Guillem |first3=Enrico |first4=Hugh R. R. |first5=Ansgar |first6=Eugenio J. |first7=Steven S. |first8=R. Paul |arxiv= 1211.1617|title= Habitable-zone super-Earth candidate in a six-planet system around the K2.5V star HD 40307|date= 2012 |doi=10.1051/0004-6361/201220268 |volume=549 |journal=Astronomy |page=A48 |bibcode=2013A&A...549A..48T}} 5. ^1 2 {{cite web |last=Wall |first=Mike |title='Super-Earth' Alien Planet May Be Habitable for Life |url=http://www.space.com/18393-alien-planet-super-earth-habitable-hd-40307g.html |date=November 7, 2012 |publisher=Space.com |accessdate=November 8, 2012 }} 6. ^{{cite web |last=Tate |first=Karl |title=Super-Earth Planet: Potentially Habitable Alien World Explained (Infographic) |url=http://www.space.com/18390-super-earth-exoplanet-habitable-zone-infographic.html |date=November 7, 2012 |publisher=Space.com |accessdate=November 8, 2012 }} 7. ^{{cite web |last=Murrin |first=Marc |title=Astronomers discover a potentially habitable Super-Earth HD 40307g (Infographic) |url=http://www.tech-stew.com/post/2012/11/08/Astronomers-discover-a-potentially-habitable-Super-Earth-HD40307g.aspx |date=November 8, 2012 |publisher=tech-stew.com |accessdate=November 8, 2012 }} 8. ^{{cite journal|arxiv=0901.1698|author=Barnes, R.|author2=Jackson, B.|author3=Raymond, S.|author4=West, A.|author5=Greenberg, R.|title=The HD 40307 Planetary System: Super-Earths or Mini-Neptunes?|journal=The Astrophysical Journal|year=2009|doi=10.1088/0004-637X/695/2/1006|volume=695|issue=2|pages=1006–1011|bibcode=2009ApJ...695.1006B}} 9. ^University of Toronto astronomer Ray Jayawardhana, author of Strange New Worlds: The Search for Alien Planets and Life beyond Our Solar System. Paraphrased in {{cite journal|url=https://www.usatoday.com/story/tech/sciencefair/2012/11/07/habitable-super-earth/1690169/|title=Habitable zone 'Super Earth' candidate planet detected|author=Dan Vergano |date=November 7, 2012}} External links
6 : HD 40307|Pictor (constellation)|Exoplanets discovered in 2012|Exoplanets detected by radial velocity|Super-Earths in the habitable zone|Exoplanets in the habitable zone |
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