Editing Definition of planet (section)

====Planetary-mass stellar objects====
The ambiguity inherent in the IAU's definition was highlighted in December 2005, when the [[Spitzer Space Telescope]] observed [[Cha 110913-773444]] (above), only eight times Jupiter's mass with what appears to be the beginnings of its own [[planetary system]]. Were this object found in orbit around another star, it would have been termed a planet.<ref>{{cite web| year=2005| author=Clavin, Whitney| title=A Planet With Planets? Spitzer Finds Cosmic Oddball| work=Spitzer Science Center| url=http://www.nasa.gov/vision/universe/starsgalaxies/spitzerf-20051129.html| access-date=May 25, 2006| archive-date=October 11, 2012| archive-url=https://web.archive.org/web/20121011011111/http://www.nasa.gov/vision/universe/starsgalaxies/spitzerf-20051129.html| url-status=dead}}</ref>

In September 2006, the [[Hubble Space Telescope]] imaged [[CHXR 73 b]] (left), an object orbiting a young companion star at a distance of roughly 200 AU. At 12 Jovian masses, CHXR 73 b is just under the threshold for deuterium fusion, and thus technically a planet; however, its vast distance from its parent star suggests it could not have formed inside the small star's [[protoplanetary disc]], and therefore must have formed, as stars do, from gravitational collapse.<ref>{{cite web|title=Planet or failed star? Hubble photographs one of the smallest stellar companions ever seen|work=ESA Hubble page|url=http://www.spacetelescope.org/news/html/heic0610.html|year=2006|access-date=February 23, 2007}}</ref>

In 2012, Philippe Delorme, of the [[Institute of Planetology and Astrophysics]] of [[Grenoble]] in France announced the discovery of [[CFBDSIR 2149-0403]]; an independently moving 4–7 Jupiter-mass object that likely forms part of the [[AB Doradus moving group]], less than 100 light years from Earth. Although it shares its spectrum with a [[T dwarf|spectral class T brown dwarf]], Delorme speculates that it may be a planet.<ref>{{cite journal|title=CFBDSIR2149-0403: a 4–7 Jupiter-mass free-floating planet in the young moving group AB Doradus?|author1=P. Delorme |author2=J. Gagn´e |author3=L. Malo |author4=C. Reyl´e |author5=E. Artigau |author6=L. Albert |author7=T. Forveille |author8=X. Delfosse |author9=F. Allard |author10=D. Homeier |journal=Astronomy & Astrophysics|year=2012|arxiv=1210.0305|doi=10.1051/0004-6361/201219984|bibcode=2012A&A...548A..26D|volume=548|pages=A26|s2cid=50935950 }}</ref>

In October 2013, astronomers led by Dr. Michael Liu of the [[University of Hawaii]] discovered [[PSO J318.5-22]], a solitary free-floating [[L dwarf]] estimated to possess only 6.5 times the mass of Jupiter, making it the least massive [[sub-brown dwarf]] yet discovered.<ref name="liu_discovery">
{{cite journal | title = The Extremely Red, Young L Dwarf PSO J318-22: A Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets | journal = Astrophysical Journal Letters | date = October 1, 2013 |author = Liu, Michael C. |author2= Magnier, Eugene A. |author3= Deacon, Niall R. |author4= Allers, Katelyn N. |author5= Dupuy, Trent J. |author6= Kotson, Michael C. |author7= Aller, Kimberly M. |author8= Burgett, W. S. |author9= Chambers, K. C. |author10= Draper, P. W. |author11= Hodapp, K. W. |author12= Jedicke, R. |author13= Kudritzki, R.-P. |author14= Metcalfe, N. |author15= Morgan, J. S. |author16= Kaiser, N. |author17= Price, P. A. |author18= Tonry, J. L. |author19=  Wainscoat, R. J. | volume = 777 | issue = 2 | doi =10.1088/2041-8205/777/2/L20 | arxiv=1310.0457|bibcode = 2013ApJ...777L..20L | pages=L20| s2cid = 54007072 }}</ref>

In 2019, astronomers at the [[Calar Alto Observatory]] in Spain identified GJ3512b, a gas giant about half the mass of Jupiter orbiting around the red dwarf star [[GJ3512]] in 204 days. Such a large gas giant around such a small star at such a wide orbit is highly unlikely to have formed via accretion, and is more likely to have formed by fragmentation of the disc, similar to a star.<ref>{{cite web|title=Exoplanet discovery blurs the line between large planets and small stars|author=Andrew Norton|date=September 27, 2019|url=https://phys.org/news/2019-09-exoplanet-discovery-blurs-line-large.html|publisher=phys.org|access-date=March 13, 2020}}</ref>