Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site psivax.UUCP
Path: utzoo!linus!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!psivax!friesen
From: friesen@psivax.UUCP (Stanley Friesen)
Newsgroups: net.space,net.astro.expert
Subject: Re: Tenth planet
Message-ID: <925@psivax.UUCP>
Date: Mon, 6-Jan-86 11:29:34 EST
Article-I.D.: psivax.925
Posted: Mon Jan  6 11:29:34 1986
Date-Received: Wed, 8-Jan-86 06:44:08 EST
References: <8512272010.AA02178@s1-b.arpa> <159@cfa.UUCP> <971@mmintl.UUCP>
Reply-To: friesen@psivax.UUCP (Stanley Friesen)
Organization: Pacesetter Systems Inc., Sylmar, CA
Lines: 35
Xref: linus net.space:3596 net.astro.expert:112

In article <971@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes:
>
>I have for some time suspected that there are a fair number of sub-stellar
>objects in the galaxy, which are not associated with any star system.
>....  Although there may be a lower limit to the size of the objects
>produced by the processes which produce stars, it seems unlikely that this
>point coincides with the ignition point.
>
>How many such objects are there likely to be?  For stars, there is a clear
>relationship between size and frequency: the smaller the size, the more
>stars there are at that scale.  There is no reason to believe this does not
>hold down to near the lower limit for the process.  Thus if objects
>appreciably smaller than .07 solar mass can be created in this way, one
>expects them to considerably outnumber the stars.  There is reason to think
>that objects as small as .0001 solar mass are possible, since this is the
>approximate size of the outer giant planets (Uranus and Neptune), which
>seem to have been formed in a similar fashion (although as part of the
>formation of the sun, not as independent events).
>
	As far as I know the mode of formation of the outer planets is
*very* close to that for stars. In fact a number of simulations
suggest that a very small change in initial conditions would have left
a small (type M or K) star where the Jovian planets are now. Given the
large number of binary(and larger) star systems, this seems quite
reasonable. Thus I see no reason at all why Uranus sized object could
not form independently also. Actually, I would expect the distribution
of sizes to peak at some point and taper off, thus the smallest
objects would likely be quite rare. But this would still leave quite a
few Jupiter/Saturn sized objects running around.
-- 

				Sarima (Stanley Friesen)

UUCP: {ttidca|ihnp4|sdcrdcf|quad1|nrcvax|bellcore|logico}!psivax!friesen
ARPA: ttidca!psivax!friesen@rand-unix.arpa