Subject: (urth) Borski-mantis Sleuthing

From: m.driussi <m.driussi at genie.com>
Date: Wed, 20 May 1998 05:31:00 +0000

Robert Borski,

Re: quote about VRT as 16 local years old, but looking older.  Great!
Okay, so a 30 hour day might be a tad long, but good enough for the
moment.

Re: the "R" of VRT, well I'll quip "Rodman" but I'm really curious to
know.

And spill the beans and genes on David's mother!

36 Ophiuchi A and 36 Ophiuchi B (18.2 ly from Earth)

(I like this one for the 3 stars, the twins, and the improbability
factor.)

"This system, consisting of 3 stars, lies almost directly between us
and the center of our Galaxy.  The orbital elements of the system
have not yet been established [in 1964].  The brightest star, 36
Ophiuchi A, is in spectral class K2, has an apparent magnitude of
5.17, and a mass about 0.77 times that of the Sun.  Thus it has a
probability of about 0.023 (or 1 chance in 43) of having a habitable
planet.  As for 36 Ophiuchi B, it is in spectral class K1, with a
mass about 0.76 times that of the Sun.  Its probability of having a
habitable planet is 0.020 (or 1 chance in 50).  This pair of stars
is very close indeed to being an example of `twin suns.'

"Here, as in the Alpha Centauri system, we might calculate the chance
of a habitable planet orbiting around either of the two brighter
components of the system.  This probability comes to 0.042 (1 chance
in 24).

"Finally, the third component, 36 Ophiuchi C, in spectral class K6,
has a mass about 0.63 times that of our Sun and is another
boarderline case for which the probability of a habitable planet is
very small" (Dole & Asimov, PLANETS FOR MAN, p. 182).

Another book, much more recent, sez that the separation for A and B
is 73.6 AU and period is 548 years: lifezones are
A and B (.35-.75 AU)
and "C" [here called 664 Ophiuchus] (.25-.53 AU).

All too low for our numbers.  (Maybe I should try a 27 hour day?)

=mantis=

*More Wolfe info & archive of this list at http://www.urth.net/urth/