迷你海王星

迷你海王星（Mini-Neptune）又称气态矮星或过渡行星，是指实际质量低于太阳系的天王星和海王星，但却和海王星相当类似的太阳系外行星。而这样的行星大气层上层会有由氢和氦组成的厚层，在之下是极深的水和氨等分子较大的挥发物。如果没有厚大气层的话，这类行星则是海洋行星^[1]。

在迷你海王星和组成成分以岩石为主的超级地球之间可能有一个分界，而这个界线可能是二倍地球半径。位于宜居带的系外行星开普勒22b与格利泽581d都是迷你海王星^[2]^[3]。

参见[编辑]

^ Optical to near-infrared transit observations of super-Earth GJ1214b: water-world or mini-Neptune? （页面存档备份，存于互联网档案馆）, E.J.W. de Mooij (1), M. Brogi (1), R.J. de Kok (2), J. Koppenhoefer (3,4), S.V. Nefs (1), I.A.G. Snellen (1), J. Greiner (4), J. Hanse (1), R.C. Heinsbroek (1), C.H. Lee (3), P.P. van der Werf (1),
^ Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates （页面存档备份，存于互联网档案馆）, Daniel C. Fabrycky, Jack J. Lissauer, Darin Ragozzine, Jason F. Rowe, Eric Agol, Thomas Barclay, Natalie Batalha, William Borucki, David R. Ciardi, Eric B. Ford, John C. Geary, Matthew J. Holman, Jon M. Jenkins, Jie Li, Robert C. Morehead, Avi Shporer, Jeffrey C. Smith, Jason H. Steffen, Martin Still
^ When Does an Exoplanet’s Surface Become Earth-Like? （页面存档备份，存于互联网档案馆）, blogs.scientificamerican.com, 20 June 2012

Six New Planets: Mini-Neptunes Found Around Sunlike Star （页面存档备份，存于互联网档案馆）, Victoria Jaggard, National Geographic News, Published February 2, 2011
Barnes, Rory; Jackson, Brian; Raymond, Sean N.; West, Andrew A.; Greenberg, Richard. The HD 40307 Planetary System: Super-Earths or Mini-Neptunes?. The Astrophysical Journal. January 13, 2009, 695 (2): 1006. Bibcode:2009ApJ...695.1006B. arXiv:0901.1698 . doi:10.1088/0004-637X/695/2/1006.