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Background Material on Titanium Oxide (TiO)

TiO is the dominant source of spectral features in cool stars and warm brown dwarfs. At temperatures below about 2000 degrees, however, a range of materials can condense out of a brown dwarf's atmosphere, several of which contain titanium. This "soaks up" the titanium which would otherwise exist as titanium oxide, weakening the titanium oxide spectral features. The chemicals which can condense out of the atmosphere to make this happen include Ti2O3, Ti4O7, and CaTiO3. While the first exist on Earth only as man made chemicals, the latter is actually a naturally occurring mineral called perovskite - though in brown dwarf atmospheres it forms as micrometre-sized smoke particles, rather than as rocks!

©Anglo-Australian Observatory 1999, PO Box 296, Epping NSW 1710 Australia

site map | search | feedback | home 7 May 1999