Primary System Details

[Tigleth Pilisar]

I've been mining the rich resources of wiki with regards to Traveller. There are several systems that have a bit of either "canon" or "non-canon" background. One thing I don't know how to read is the Primary System Details. This refers somehow to the planets within a parsec system, gas giants moons and the such, I think.

Does anyone know how to read them? Things like:

M6 V
A6 V
G9 V
M3 V M7 D
K8 V
F6 V M7 V

How do they describe the planetary orbits?

 

[Bense]

Those don't describe the orbits - they are the star spectral types (from real-life star classifications).
The first letter is the basic type, the number is where it fits within the type, and the letter at the end is the size. V is a main sequence star, and D is a dwarf (I, II, and III are giants, IV is a subgiant, V is the "main sequence" - the size of our sun, VI and VII are slightly larger dwaf stars).
M stars are the coolest types, A is one of the warmest (the order, from hottest to coldest, is O,B,A,F,G,K,M).
If there are two or more stars then the first one is the star the mainworld orbits, and the others are companion stars.

 

[Tigleth Pilisar]

Thank you. Lots of physics I never learned.

 

[DFW]

I found this a while ago.


http://www.4shared.com/document/On8PXPCu/Stars.html

 

[rust]

Does anyone know how to read them? Things like:

M6 V
A6 V
G9 V
M3 V M7 D
K8 V
F6 V M7 V

How do they describe the planetary orbits?

While these are star classifications, not orbital data, it is still possible to
use them to estimate where the habitable zone of a system is, and where
therefore the orbit of the mainworld is most likely to be.

With the examples above, a mainworld in orbit around the M6 V star will
be comparatively close to it, and probably tide locked to it, while a main-
world in orbit around the F6 V star will be much farther away from it.

The star classification also gives an impression of the possible age of the
system. For example, an A6 V star remains a main sequence star for on-
ly about 2 billion years, so its planet is still very young, could well still be
quite hot, and most probably has not developed any native life yet - and
will become uninhabitable in the not so far future.