Editing Brown dwarf (section)

=== Unusual brown dwarf binaries ===
[[File:SDSS J1416+1348 legacy dr10.jpg|thumb|The wide brown dwarf binary [[SDSS J141624.08+134826.7|SDSS J1416+1348]]]]
The wide binary system [[2M1101AB]] was the first binary with a separation greater than {{Val|20|ul=AU}}. The discovery of the system gave definitive insights to the formation of brown dwarfs. It was previously thought that wide binary brown dwarfs are not formed or at least are disrupted at ages of 1–10 [[Myr]]. The existence of this system is also inconsistent with the ejection hypothesis.<ref>{{cite journal |last=Luhman |first=Kevin L. |date=2004-10-10 |title=The First Discovery of a Wide Binary Brown Dwarf |journal=The Astrophysical Journal |volume=614 |issue=1 |pages=398–403 |arxiv=astro-ph/0407344 |doi=10.1086/423666 |issn=0004-637X |bibcode=2004ApJ...614..398L |s2cid=11733526 }}</ref> The ejection hypothesis was a proposed hypothesis in which brown dwarfs form in a multiple system, but are ejected before they gain enough mass to burn hydrogen.<ref>{{cite journal |last1=Reipurth|first1=Bo|last2=Clarke|first2=Cathie|date=June 2003|title=Brown Dwarfs as Ejected Stellar Embryos: Observational Perspectives|journal=IAUS|volume=211|pages=13–22|issn=1743-9221|bibcode=2003IAUS..211...13R|arxiv=astro-ph/0209005|doi=10.1017/s0074180900210188|s2cid=16822178 }}</ref>

More recently the wide binary [[W2150AB]] was discovered. It has a similar mass ratio and [[Gravitational binding energy|binding energy]] as 2M1101AB, but a greater age and is located in a different region of the galaxy. While 2M1101AB is in a closely crowded region, the binary W2150AB is in a sparsely-separated field. It must have survived any dynamical interactions in its natal [[star cluster]]. The binary belongs also to a few L+T binaries that can be easily resolved by ground-based observatories. The other two are [[SDSS J1416+1348|SDSS J1416+13AB]] and Luhman 16.<ref>{{cite journal |last1=Faherty |first1=Jacqueline K. |last2=Goodman |first2=Sam |last3=Caselden |first3=Dan |last4=Colin |first4=Guillaume |last5=Kuchner |first5=Marc J. |last6=Meisner |first6=Aaron M. |last7=Gagné |first7=Jonathan |last8=Schneider |first8=Adam C. |last9=Gonzales |first9=Eileen C. |last10=Bardalez Gagliuffi |first10=Daniella C. |last11=Logsdon |first11=Sarah E. |title=WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9 |journal=The Astrophysical Journal |volume=889 |issue=2 |pages=176 |arxiv=1911.04600 |doi=10.3847/1538-4357/ab5303 |year=2020 |bibcode=2020ApJ...889..176F |s2cid=207863267 |doi-access=free }}</ref>

There are other interesting binary systems such as the [[eclipsing binary]] brown dwarf system [[2MASS J05352184–0546085]].<ref name="Stassun2006"/> Photometric studies of this system have revealed that the less massive brown dwarf in the system is hotter than its higher-mass companion.<ref name=":1" />