[I admitted to being somewhat rusty on my astronomy hobby. Now everyone
listen up for these corrections/additions/clarifications.
- --jamesp@dadla.wr.tek.com]
Recently, there was a posting regarding stellar information for someone
who wanted "real" star system generation information. Some of the material
in there was not quite correct and some was wrong. I will attempt to clear
up a few things.
First, stellar classification is done by 1) mass, 2) temperature, 3) (much
less important) composition. The third point is usualy equivalent to
age, but not always. All stars go through several evolutionary stages
which are more or less the way they were described in the previous posting.
Mercury is *not* tide locked. It was believed to be tide locked into the
sixties, and some *current* text books still list it as tide locked, although
it most certainly is not. This is certainly an easy mistake to make given
the state of astronomical literature, but it is a mistake, none the less.
Stars in globular clusters. Don't worry about it in a Traveller universe.
It is possible that a planetary system could develop and could remain
relatively stable within a globular cluster for billions of years. It is
also very possible that the system would be torn to shreds by a star passing
nearby, it depends on the circumstances. You don't need to worry about
systems in globulars because 1) they're very old, which means they're *very*
metal poor. Therefore, not only is civilization unlikely to develop there,
but nobody except scientists would want to go there (personally, I'd give
up several limbs to get a close look at one.), 2) They are so far away
(on the order of 50,000 light years) so that without a massive advance in
primary drive technology, nobody will get there.
Binary stars can be contact binaries (literally touching each other) to
very distant binaries (on the order of a couple of light years). They
can also be anything in between. If the stars are close enough, distant
planets can pretty much treat them as a single star (see variable stars
below, though). If they are distant enough, a planet can treat them as
two separate stars; orbit one and ignore the other. If the system is
one main star with a companion orbiting in a planet-like orbit (distance
wise) foget it. Not only are no stable orbits possible, (assuming
both stars are massive enough to be significant) but humans and human-like
life couldn't survive the radical climatic changes. Other life forms,
however, might be able to. The instability of the orbits is a *real*
problem, though.
Other system types? How about a planet orbiting a variable star. All
close (contact) binaries will be variable. Unless you are very high
tech, or very adaptable, or really weird, you (as a species) will not
be able to survive in a variable star system like an RR Lyrae, delta
Cepei, W Virginis, omicron Ceti, U Geminorum or other "well known"
variable star type. Good for curiosities and weird adventures, though.
Flare stars and X-ray binaries pose a special hazard to travellers.
All of these stars in the shattered imperium will be well known and
*very* well studied. I would also guess that with the possible exception
of Semi-regular red giants and ZZ Ceti type stars, their periods will
be very well known, especially by Travellers.
I hope this helps. If there are any questions, let me know.
Nick Christenson
[email removed]
#include <disclaimer.h>