"Binary" appears to be Nature's preferred mode for forming stars.
- More than 50% of all stars exist in small multiple systems with
equal numbers in equal logarithmic intervals of the period. [Abt 1983]
- There appear to be very different secondary-mass distributions
for binaries with periods less than or greater than 100 years. [Abt 1983]
- The frequency of binaries in star forming regions appears to be very
similar to the frequency on the main sequence. [Mathieu et al. 1994]
Although many many numerical simulations have been performed over
the past two decades in an effort to show to what extent a "Jeans-type"
fragmentation occurs during the collapse of a rotating, protostellar
gas cloud, two major problems exist regarding our understanding
of how binary stars form [Bodenheimer 1995; see also Shu et al. 1987]:
Simulations show that
"the most likely initial condition in the
core of a molecular cloud [i.e., a centrally condensed
configuration] appears to be stable against
- "... the theoretical difficulty in forming close binaries;
almost all the current simulations produce relatively wide
- Orbital Decay.
- Disk fragmentation.