Why are massive main-sequence stars not
likely to have planets that contain life?
1. The life zones around these stars are too
small.
2. These stars would sweep away all of the
material from which planets could form.
3. These stars are on the main sequence for
too short a time to alllow life to evolve
4. These stars are too hot to allow water to
exist as a liquid on any planets that might
form.
5. These stars are almost always binaries
and planetary orbits are unstable around bi-
naries.