Editing Brown dwarf (section)

==== Size and fuel-burning ambiguities ====
Brown dwarfs are all roughly the same radius as Jupiter. At the high end of their mass range ({{Jupiter mass|60–90}}), the volume of a brown dwarf is governed primarily by [[degenerate matter|electron-degeneracy]] pressure,<ref>{{cite journal |title=Planetesimals to Brown Dwarfs: What is a Planet? |date=2006-08-20 |pages=193–216 |first1=Gibor |last1=Basri |last2=Brown |first2=Michael E. |author-link2=Michael E. Brown |volume=34 |issue=2006 |doi=10.1146/annurev.earth.34.031405.125058 |journal=[[Annual Review of Earth and Planetary Sciences]] |arxiv=astro-ph/0608417 |bibcode=2006AREPS..34..193B|s2cid=119338327 }}</ref> as it is in white dwarfs; at the low end of the range ({{Jupiter mass|10}}), their volume is governed primarily by [[Coulomb barrier|Coulomb pressure]], as it is in planets. The net result is that the radii of brown dwarfs vary by only 10–15% over the range of possible masses. Moreover, the mass–radius relationship shows no change from about one Saturn mass to the onset of hydrogen burning ({{val|0.080|0.008|u=M_Solar}}), suggesting that from this perspective brown dwarfs are simply high-mass Jovian planets.<ref name="ChenKipping">{{cite journal |last1=Chen |first1=Jingjing |last2=Kipping |first2=David |date=2016 |title=Probabilistic Forecasting of the Masses and Radii of Other Worlds |journal=The Astrophysical Journal |volume=834 |issue=1 |page=17 |arxiv=1603.08614 |doi=10.3847/1538-4357/834/1/17 |s2cid=119114880 |doi-access=free |bibcode=2017ApJ...834...17C }}</ref> This can make distinguishing them from planets difficult.

In addition, many brown dwarfs undergo no fusion; even those at the high end of the mass range (over {{Jupiter mass|60}}) cool quickly enough that after 10&nbsp;million years they no longer undergo [[deuterium burning|fusion]].