Brown-dwarf desert

A brown-dwarf desert is an orbital distance around a star at which brown dwarfs cannot exist as binary stars. [cite book | title = Planet Formation: Theory, Observations, and Experiments | author = Hubert Klahr and Wolfgang Brandner | publisher = Cambridge UniversityPress | year = 2006 | isbn = 0521860156 | url = http://books.google.com/books?id=CukAzsJHQaQC&pg=RA5-PA241&dq=brown-dwarf-desert&lr=&as_brr=0&ei=d5a9R_-kBYmoiQHU9sXnCA&sig=w0aaVbMkwbPZ_28dUfKmOrt2nyQ ] This is usually up to 5 AU around solar mass stars.

This desert occurs because if a brown dwarf was to form it would have to do so at the same time as its companion star. If the brown dwarf forms within 5 AU of its companion star it would begin migration towards the star and eventually become consumed by the larger star.

It has recently been observed that very-low-mass binaries could destroy the theory of brown-dwarf deserts. This is because low-mass binaries are seen to orbit within 5AU; however, due to the low mass of the larger companion, this matter is still a topic of debate.

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