Editing Planetary system (section)

====Planets and stars====
{{main|Planet-hosting stars}}

[[Image:Morgan-Keenan spectral classification.svg|300px|thumb|right|The Morgan-Keenan spectral classification]]
Most known exoplanets orbit stars roughly similar to the [[Sun]]: that is, [[main sequence|main-sequence stars]] of [[stellar classification|spectral categories]] F, G, or K. One reason is that planet-search programs have tended to concentrate on such stars. In addition, statistical analyses indicate that lower-mass stars ([[red dwarf]]s, of [[stellar classification|spectral category]] M) are less likely to have planets massive enough to be detected by the [[radial-velocity method]].<ref name="cumming08">{{Cite journal| author=Andrew Cumming|date=2008|title=The Keck Planet Search: Detectability and the Minimum Mass and Orbital Period Distribution of Extrasolar Planets|journal=Publications of the Astronomical Society of the Pacific|volume=120| issue=867|pages=531–554| arxiv=0803.3357|doi=10.1086/588487| bibcode=2008PASP..120..531C| author2=R. Paul Butler| author3=Geoffrey W. Marcy| last4=Vogt| first4=Steven S.| last5=Wright| first5=Jason T.| last6=Fischer| first6=Debra A.|s2cid=10979195| author-link3=Debra Fischer | display-authors=3}}</ref><ref name="bonfils05">{{Cite journal |doi=10.1051/0004-6361:200500193 |title=The HARPS search for southern extra-solar planets VI: A Neptune-mass planet around the nearby M dwarf Gl 581 |journal=Astronomy and Astrophysics |volume=443 |issue=3 |pages=L15–L18 |year=2005 |last1=Bonfils |first1=Xavier |last2=Forveille |first2=Thierry |last3=Delfosse |first3=Xavier |last4=Udry |first4=Stéphane |last5=Mayor |first5=Michel |last6=Perrier |first6=Christian |last7=Bouchy |first7=François |last8=Pepe |first8=Francesco |last9=Queloz |first9=Didier |last10=Bertaux |first10=Jean-Loup |bibcode=2005A&A...443L..15B |arxiv=astro-ph/0509211 |s2cid=59569803 }}</ref> Nevertheless, several tens of planets around red dwarfs have been discovered by the [[Kepler space telescope]] by the [[transit method]], which can detect smaller planets.