Sytem Codes for Planets in Wiki

[Tigleth Pilisar]

I like the well developed Traveller 3rd Imperium stuff in Wiki.

But who can interpret this for me:
(I get this part):
Shirene/Lunion (Spinward Marches)
Classic Era (1115) B984510-BStarport B Good: Spacecraft Construction, Overhaul, Refined fuel
Size 9 Large (14,400 km)
Atmosphere 8 Dense
Hydrographics 4 Wet World 40%
Population 5 Moderate (700 thousand)
Government 1 Company/Corporation
Law 0 No Law
Tech Level B Average Stellar (large starships)

(I don't get this part)
Primary G4 V M1 D M1 D
Gas Giants 5
Planetoid Belts 2

I think this means there is a type G star (same as earth) with 4 luminosity (don't really know if that is bright or what), I think the V means a normal sun, but not sure. Then the two "M1 D" things, does that mean there are two more stars in the system? A triple star system? M being type of star (meaning it is red and cooler than our sun) 1 being maybe very low luminosity? and the D meaning it is a Dwarf star?

Is that what this means?

I guess there are 5 gas giants in two elipses around the V sun? Or 5 gas giant elipses and then 2 additional elipses for planets?

Thanks.

 

[BP]

You've got the gist, I think - though the 2 planetoid belts means there are 2 major asteroid belts; the orbits of the Gas Giants (and anything else for that matter) are not defined in this system.

 

[Jeraa]

I don't think the D means a dwarf star. Main sequence stars are all dwarf stars, but the primary star doesn't have that notation. If they were red dwarfs, they would be M1 V, not M1 D.

After further looking, I can't find anything on what a M1 D star would be. The only classifications I've found are O, I, II, III, IV, V, and VII. As far as I can tell, D is never used. So someone made a typo, or whatever system was used to generate that star system has its own rules.

(Well, D is used, but not at the end. Its for white dwarfs, like Sirius B [DA2] and Procyon B [DA4].)

 

[renski]

I like the well developed Traveller 3rd Imperium stuff in Wiki.
(I don't get this part)
Primary G4 V M1 D M1 D
Gas Giants 5
Planetoid Belts 2

You've almost got it. Ok, the first letter is the star is the Havard Spectral Classification, which is often remembered by the mnemonic.

Oh Be A Fine Girl, Kiss Me. This spectral classification gives you an idea what colour the star is.

O - Blueish White (as most of their output is in the ultraviolet)
B - Blue
A - Blueish White
F - Light Yellow
G - Yellow (like our own sun)
K - Orange
M - Red

Similarly, the scale also tells you how hot the star is. O is the hottest, where as M is the coolest. The number after the letter tells where within that class the star is. The lower the number, the lower down the spectrum the star is. So a M1 would be redder and cooler than a M2 star, but a M2 star is cooler than a K1 star.

The numbers afterwards is the Yerkes spectral classification, this tells you the size, 0 being the largest, 7 (VII) being the smallest. Our sun, is a type V, a main sequence dwarf. Sometimes you'll see this classification subdivided by lowercase letters. So the sequence is 0, Ia, Iab, Ib, IIa, IIab, Ib, IIIa...and so on.

So in your case we've got G4 V. This sun is about the same size as ours, but slightly brighter and hotter. Our sun is a G2 V.

M1 stars are very red and very cool. The 'D' is nonsense, I think the author may be thinking dwarf. But M1s are typically type V dwarfs. Sub Dwarfs type VI can sometimes be denoted by sD. Perhaps that's where the confusion got in. Personally id call it a M1 V. I think very large M stars are possible, but not orbiting a G4 V.

Gas Giants 5
Planetoid Belts 2

and yeah, it's got five gas giants and 2 belts.

Renski

 

[renski]

Great Diagram Here

http://cococubed.asu.edu/images/hr_diagrams/hr_fancy.jpg

 

[renski]

Just found this, a 'D' and VII are the same thing. A D is a white dwarf.

https://www.cfa.harvard.edu/~pberlind/atlas/htmls/note.html

 

[Gypsy Knights Games]

M1 stars are very red and very cool. The 'D' is nonsense, I think the author may be thinking dwarf. But M1s are typically type V dwarfs. Sub Dwarfs type VI can sometimes be denoted by sD. Perhaps that's where the confusion got in. Personally id call it a M1 V. I think very large M stars are possible, but not orbiting a G4 V.

This is a left-over from older Traveller systems. If you look over data from the MegaTraveller years, you will find this sort of thing quite a bit.

I highly recommend giving this revised generation table by Constantine Thomas a look. I think it may clear up a lot of your questions.

 

[BP]

Just found this, a 'D' and VII are the same thing. A D is a white dwarf.

https://www.cfa.harvard.edu/~pberlind/atlas/htmls/note.html

Yep - there are a number of RL classification systems that have been used and Harvard's was one of the establishing ones. Classic Traveller used D as well as VII, at least in the version of Scouts that I had.

 

[Tigleth Pilisar]

Thanks!!