			    TRAVELLER Digest 170

Topics covered in this issue include:

  1) Re: YARS: Fixing anomalous stars....	by "Harold D. Hale" <hdhale@smtpwpo.dayt.tasc.com>

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Date: Mon, 23 Jan 1995 12:22:19 -0500
From: "Harold D. Hale" <hdhale@smtpwpo.dayt.tasc.com>
To: traveller@MPGN.COM
Subject: Re: YARS: Fixing anomalous stars....
Message-ID: <sf239f0a.096@smtpwpo.dayt.tasc.com>

>    A very long time ago, several Traveller players noticed that  the
>standard sector files had some, well, "peculiar" (read:   stupid)
>combinations of worlds and stars.

   Kaguk (the name shorten for Terran pallets I guess some years ago)
is another classic example.  It is an agricultural world that at according
to the old listings orbited around a M3 D star!  That's not even enough
wattage to grow mushrooms.  In fact, the temperature of such a world
(regardless of its orbit) would likely be so cold that it could not even
have an atmosphere.

>    Some time back (last month), Harold Hale proposed that, while 
>visiting Viral destruction on your favorite systems, Referees  take the
>time to fix some of those weird world-star combos.  He  outlined some
>thumbrules* for doing so that would change things  to better match
>observed stellar frequencies, and make sense,  too.  I said, "Great!",
>clipped and filed the article, and  continued with Christmas planning. 

   The work was not mine alone, though certainly I was thinking along
the same lines as the other individuals who should get a share of the
credit.  They are (and I apologize profusely if I forget anyone):

   Mark "Geo" Gelinas - who developed a supplement to the Collapse
Effect rules which updated the primary stars of the standard sector
files.

   Leroy "Hindmost" Guatney - who acted as sounding board, well of
knowledge, and verbal sparring partner as I began my  Holy Quest for
Astronomical Correctness.  His involvement with Traveller dates back
long before Book 6: Scouts, and he is an amateur astronomer to boot.
Leroy is currently working on a new stellar generation system which
will be proposed at some point in the future as a replacement for the
current "House System" (which still has its flaws, though it should be
noted is much improved over previous versions).

>    Since I like to write programs for the fun of it, and I find  rolling
dice
>for n-thousand worlds really, really tedious, I  decided to write Yet
>Another Rexx Script to do the job, to be  called SUNFIX.CMD.  

   I'd like a copy of this, if possible, Cynthia.  I don't mind rolling dice,
but wouldn't mind a break....

>Howard Hale's algorithm

   Name's Harold.  Howard is my evil twin who only comes out at night
when the moon is full.   :-)

>    While you're destroying interstellar civilization at the  local level,
you
>may also want to take the time to correct  anomalous stellar data.  All
>class "D" stars which are primaries  (particularly with a main world that
>is even marginally  habitable) should be changed to class "V"; all class
>"VI" stars  should be "V" stars; all K5 through M9 class "IV" should be 
>changed to class "V".  
>
>** why: There are no class VI stars; ditto for K5 thru M9 IV stars.

Additional Notes

clarification: There are class VI stars, *but* because of their nature
(lacking in any elements above helium-- therefore, no planets,
asteroids, or even comets), they are not portrayed in the game.
Solo white dwarfs also usually lack planetary bodies--the evolution
of the star from main sequence to giant to white dwarf normally cooks
away all the planetary bodies in a system.  Occasionally, though, a
planet or two might survive--a Pluto-like body or on rare
occasions an outer  gas giant.  No exceptions are made for this in
Geo's conversion guidelines, *but* if you want to add a bit of realism
(and don't mind the extra hassle of there being an exception to the
rule), keep two or three white dwarf primaries--a "qualified" candidate
should consist of a O - K white dwarf, with a main world that has an
atmosphere of 1 or less.  A gas giant or two may be present, but no
world can be any closer than orbit 5 or 6.

addition: True, 'B' class white dwarfs have a habitable zone, but the
nature of white dwarf star systems (see above) would preclude the
possibility of there being a world that close to the star, barring Ancients
manipulation (read: for all practical purposes non-existent).  Also,
every white dwarf out there was  at one time a red giant star.
This fact would preclude star systems that consist of a primary with a
white dwarf in close orbit and a habitable planet in orbit 2-4 (or so)
from existing (the habitable planet would at one time have been inside
the envelope of the red giant and been destroyed).


>    Now that you've fixed the primaries, look at the companions.   I
>decided that Harold's method of going back and forth counting  white
>dwarfs and adjusting the count was too much of a hassle for  a
>one-pass program; I assigned a flat 33% chance that an existing
>M type "D" white dwarf would remain a white dwarf, albeit changed  in
>spectral class, or turn into a 'V'.  

   33 percent...humm...I decided on changing all the white dwarfs to
'M' type main sequence stars first (and then reconverting some of them
later) because I wanted to radically reduce the number of so-called
'DM' companions.  I'm curious, Cynthia, on the average number of
white dwarfs per subsector that results from your method.  Some of the
old standard sector files had a DM in over half the star systems, while
others had lesser amounts because they where generated much later.

>Use the following table  to assign the new spectral class.

   This table is reflective of the white dwarf frequency as we know
it to exist today.  Notice that 'K' and 'A' class white dwarfs are the
most common type, unlike main sequence stars which have the
distribution listed in Cynthia's post ('M' class being the most common, then
'K', 'G', etc.).

>** why change spectral class?  The universe isn't old enough for  there
>to be very many M white dwarfs, and they'd be in Population
>II clusters, not the Population I areas where Traveller is set.

   There was a raging debate between Leroy and myself over the
question of whether 'M' class white dwarfs should even be included
at all on the white dwarf class tables (I held out that they shouldn't be,
he countered that they should).  The result was a compromise which
allows them to occur, but very infrequently.  'M' class white dwarfs
are theoretically (I say theoretically because so far, none have been
confirmed to exist, though there is at least one K9 D out there)
extremely old white dwarfs, on the order of 8 to 10 billions years, 
which could be population I or II stars.  They almost certainly *can not*
be found as companions of young 'O', 'B', 'A' or even 'F' or 'G' class
main sequence stars ('K' class main sequence would be borderline
at best) as the combination would be akin to having a 80 year old man
and a 20 year old man who were brothers by the same mother.

>Some other useful stats:

   Interesting information which could open up a whole discussion of
playability vs. realism and the basis of the 1 parsec hex system, and
why all the stars *shouldn't* be shown on the map, but I'll save it for
later....


Harold


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End of TRAVELLER Digest 170
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