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R.P. Olling (USNO/USRA)
I evaluate the rate of known binaries in past and present catalogs. The binarity/multiplicity rate is a strong function of both distance and apparent magnitude, suggesting that strong selection effects are at work. The sample of brightest & closest stars have a binary rate of 90-95%. Angular momentum considerations suggest that star formation is not possible without "dumping" the initial angular momentum of the proto-stellar cloud onto a compaion. We thus suggest that in fact 100% of stars are member of a multiple system, where the companion(s) may be either/or/and stars, brown dwarf, or planets.
Previous | Session 107 | Next
Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.