Suggestion for T5SS and stellar data

[Garnfellow]

That's because it isn't in the books (which I am presuming is an oversight on the part of the publishers). I looked everywhere in those books when I got them to find the notation-key, and pulled my hair out doing it, to no avail.

My source for the notation syntax above comes from an e-mail forwarded to me by DonM in which Mike West details from memory long afterward what he remembers the notation to be.

That's helpful, thank you. Looking through the Bearers of the Flame data, where there are instances of brackets and parentheses together, it certainly appears to follow the Mike West explanation, but the use is very, very inconsistent. Whole sectors don't seem to use any parentheses, just brackets. In context one can often tell what brackets are likely near companions and what are far companions.

 

[Garnfellow]

Proposal for Notation

After looking through the Bearers of the Flame book and playing around with the T5 stellar generation data, it seems like Dalthor's proposal might work very well:

Primary star and companion: no notation
Close star and companion appear within parentheses
Near star and companion appear within curly braces
Far star and companion appear within square brackets

So the fabled 8 star system would look like this:

P c (C c) {N c} [F c]

Castor would look something like this:

A1 V M5 V {A2 V M2 V} [M0.5 V M0.5 V]

To put it another way, parentheses denote stellar objects in the inner system exclusive of the primary and its companion, curly braces denote stellar objects in the outer system, and square brackets denote stellar objects in a remote system.

An asterisk would denote which stellar system the mainworld orbits.

 

[DonM]

Does that mean that the issue is dead, or just on the back-burner?

So back-burner it's not even funny.

And the last consideration of Castor (Solo 2339) for T5 was

(A1 V M5 V) (A2 V M2 V) [M1 V M1 V]

Remember that anything in [] is not considered to influence the other stars.

But we're not doing anything with parsing this year.

 

[aramis]

So back-burner it's not even funny.

And the last consideration of Castor (Solo 2339) for T5 was

(A1 V M5 V) (A2 V M2 V) [M1 V M1 V]

Remember that anything in [] is not considered to influence the other stars.

But we're not doing anything with parsing this year.

So, if I were to parse this out...

A1V M5V are a close pair
the A2V M2V are a close pair, and their orbit is basically around the A1V/M5V...
and then, a light day or more away, is a pair of M1V's...

So

12-----34---------------------–––––-56

 

[DonM]

However, the question then is, does that actually represent Castor, which is what it is supposed to represent?

 

[aramis]

However, the question then is, does that actually represent Castor, which is what it is supposed to represent?

Wikipedia gives the following

Aa: A1 V Unknown
Ab: (probably M5 V)
Ba: A2 Vm
Bb: M2 V
Ca: M0.5 Ve
Cb: M0.5 Ve
Distance 51±3 LY
Separation
A to B: 0° 0' 5"
A to C: 0° 1' 11"
​

51 LY * sin(5") is about 10.83 LH (Orbit 9)
51 LY * sin(71") is about 6.408 LD (Orbit 15 ish)

This does work if () indicates "Within Close of each other" and [] indicates "enclosed far from system barycenter"...
But implies we've a missing parenth set.

So:
(A1 V M5 V) (A2 V M2 V) [(M1 V M1 V)]...
This is because the distance between each pair is below 1" of arc... and thus below about 1 LH.

Looking further:
http://www.jodrellbank.manchester.ac.uk/astronomy/nightsky/AList/Gemini.html gives

Aa Ab coorbit: 9.2 days
Ba Bb coorbit: 2.9 days
Ca Cb coorbit: 2 hours
​

All of these were discovered as spectroscopic binaries, not visual ones, from the visual A B C...

Ca Cb is probably orbit -1.
Ba Bb is also probably orbit 0
Aa Ab is also probably orbit 0, maybe orbit 1. but I can't recall and am too lazy to find the formulae for those at the moment.

 

[whulorigan]

[FONT=arial,helvetica]

Wikipedia gives the following

Aa: A1 V Unknown
Ab: (probably M5 V)
Ba: A2 Vm
Bb: M2 V
Ca: M0.5 Ve
Cb: M0.5 Ve
Distance 51±3 LY
Separation
A to B: 0° 0' 5"
A to C: 0° 1' 11"
​

51 LY * sin(5") is about 10.83 LH (Orbit 9)
51 LY * sin(71") is about 6.408 LD (Orbit 15 ish)

This does work if () indicates "Within Close of each other" and [] indicates "enclosed far from system barycenter"...
But implies we've a missing parenth set.

So:
(A1 V M5 V) (A2 V M2 V) [(M1 V M1 V)]...
This is because the distance between each pair is below 1" of arc... and thus below about 1 LH.

Looking further:
http://www.jodrellbank.manchester.ac...st/Gemini.html gives

Aa Ab coorbit: 9.2 days
Ba Bb coorbit: 2.9 days
Ca Cb coorbit: 2 hours
​

All of these were discovered as spectroscopic binaries, not visual ones, from the visual A B C...

Ca Cb is probably orbit -1.
Ba Bb is also probably orbit 0
Aa Ab is also probably orbit 0, maybe orbit 1. but I can't recall and am too lazy to find the formulae for those at the moment.

[/FONT][FONT=arial,helvetica]

Aramis is correct. To be absolutely clear, nested parentheses, braces and/or brackets may be necessary for any given configuration.

The problem is that for the notation listed for Castor, the Aa/Ab components at Orbit-0 or Orbit-1 would form a "Close Star" set, not Companions, and likewise for the Ba/Bb components, respectively. Let's assume for a moment for the sake of argument that Ab orbits Aa in Orbit-1, and Bb orbits Ba in Orbit-1, respectively. This means that in each sub-system there could be a potential object in Orbit-0. Now you cannot use the [/FONT][FONT=arial,helvetica][FONT=arial,helvetica][FONT=arial,helvetica](A1 V M5 V) for the A-Component and (A2 V M2 V) for the B-Component, as they are no longer close companions about which all objects orbit both stars in the set.

[/FONT][/FONT]So using EDG's notation under the T5 definitions would lead to ambiguity:
[/FONT]

[FONT=arial,helvetica][FONT=arial,helvetica]A1 V M5 V A2 V M2 V [(M1 V M1 V)][/FONT][/FONT]
​

[FONT=arial,helvetica]If I use Garnfellow's proposed T5-modification of EDG's notation, based on Aramis's data above Castor would be:

[/FONT][FONT=arial,helvetica](A1 V M5 V) {(A2 V M2 V)} [M1 V M1 V]

since under T5:
[/FONT]

[FONT=arial,helvetica]Aa & Ab are Close Stars of one another;[/FONT]
[FONT=arial,helvetica][FONT=arial,helvetica]Ba & Bb are Close Stars of one another;[/FONT][/FONT]
[FONT=arial,helvetica][FONT=arial,helvetica][FONT=arial,helvetica][FONT=arial,helvetica]Ca & Cb are Companion Stars of one ano0ther;[/FONT][/FONT][/FONT][/FONT]
​

[FONT=arial,helvetica]the A-B components would be near-binaries of one another;
the A-C components would be far-binaries of one another.

where:
[/FONT]

[FONT=arial,helvetica]<no parsing> = Companion Stars[/FONT]
[FONT=arial,helvetica]( ) = Close Stars[/FONT]
[FONT=arial,helvetica]{ } = Near Stars[/FONT]
[FONT=arial,helvetica][ ] = Far Stars
[/FONT]​

[FONT=arial,helvetica]NOTE: I just realized we have another set of parsing symbols if necessary: < >. These could be used for Companion Stars, if desired. [/FONT]

 

[dalthor]

[FONT=arial,helvetica]


where:
[/FONT]

[FONT=arial,helvetica]<no parsing> = Companion Stars[/FONT]
[FONT=arial,helvetica]( ) = Close Stars[/FONT]
[FONT=arial,helvetica]{ } = Near Stars[/FONT]
[FONT=arial,helvetica][ ] = Far Stars
[/FONT]​

[FONT=arial,helvetica]NOTE: I just realized we have another set of parsing symbols if necessary: < >. These could be used for Companion Stars, if desired. [/FONT]

I use no notation for the primary and its companion.

Anything in parenthesis is Close, and may include the close companion

Anything in curly braces is Near, and may include the near companion

Anything in square brackets is Far, and may include the far companion.

This is the simplist notation I could come up with that met the T5 standard and allowed the referee to distinguish which stars are where.

 

[dalthor]

I don't want to get into hyper-detail here, just trying to figure out which star, based on mass, would typically be the primary. I also realize that if there is a companion, this may also have an effect.

With regard to stellar objects, in really simple terms, as this layman understands it, and not getting really technical --

O stars are hottest and generally the most massive, then type B, then A, thru the OBAFGKM series. I'm ignoring the other classifications out there, dealing mainly with them as used in T5.

Then they have a digit 0-9 to break it down further within that class, so a G0 is hotter than a G9.

So, IN GENERAL, where ">" means "is more massive than"

O1 > O9 > B0 > B9 > A0 > A9 > F0 > G > K > M

The luminosity, 1a - VII, is more for brightness than mass.

Is this essentially correct?

This all ties back to updating MTU based on the data files I can pull from the TravMap site.

Ed

 

[whulorigan]

With regard to stellar objects, in really simple terms, as this layman understands it, and not getting really technical --

O stars are hottest and generally the most massive, then type B, then A, thru the OBAFGKM series. I'm ignoring the other classifications out there, dealing mainly with them as used in T5.

Then they have a digit 0-9 to break it down further within that class, so a G0 is hotter than a G9.

So, IN GENERAL, where ">" means "is more massive than"

O1 > O9 > B0 > B9 > A0 > A9 > F0 > G > K > M
.
.
.
Is this essentially correct?

Yes, this is correct.

The luminosity, 1a - VII, is more for brightness than mass.

Is this essentially correct?

Yes, luminosity has to do with brightness (Ia brightest thru VII [or D] dimmest). But keep in mind also that brightness is typically related to physical size (i.e. Ia is a "Bright Supergiant" and VII [D] is a Degenerate ["White"] Dwarf. "V" is a "normal/typical" Main-Sequence Dwarf star (like our Sun), IV is a Sub-Giant, and VI is a Sub-Dwarf.

And be aware that the "Main-Sequence Dwarf" (Class V) stars fall along that diagonal band called the Main Sequence, meaning that an O# V star is also much brighter (and larger) than a G# V star, which is much larger (and brighter) than a M# V star.

 

[Garnfellow]

I use no notation for the primary and its companion.

I agree that a specific notation for companion stars is unnecessary; if two stars appear next to each other they would be considered companions.

Although the T5 stellar generation rules don't allow it, this notation can capture even more complex configurations. For example, a far star can only be associated with a close companion. But the Dalthor notation would let us capture something like this:

A2 V {M6 V} [K1 V {M3 V}]

A system with an A2 V primary orbited by an M6 V star in a near orbit, and a far K1 V star orbited by an M3 V star in near orbit.

 

[Garnfellow]

Out of curiosity, I wanted to see what the odds were of rolling different stellar configurations in T5. There are 54 different types of possible systems:

Number of Stars	P	Odds
1	P	48.2253%
2	P [F]	08.0376%
2	P {N}	08.0376%
2	P Pc	09.6451%
2	P (C)	08.0376%
3	P [F Fc]	01.6075%
3	P {N} [F]	01.3396%
3	P Pc [F]	01.6075%
3	P (C) [F]	01.3396%
3	P {N Nc}	01.6075%
3	P Pc {N}	01.6075%
3	P (C) {N}	01.3396%
3	P Pc (C)	01.6075%
3	P (C Cc)	01.6075%
4	P {N} [F Fc]	00.2679%
4	P Pc [F Fc]	00.3215%
4	P (C) [F Fc]	00.2679%
4	P {N Nc} [F]	00.2679%
4	P Pc {N} [F]	00.2679%
4	P (C) {N} [F]	00.2233%
4	P Pc (C) [F]	00.2679%
4	P (C Cc) [F]	00.2679%
4	P Pc {N Nc}	00.3215%
4	P (C) {N Nc}	00.2679%
4	P Pc (C) {N}	00.2679%
4	P (C Cc) {N}	00.2679%
4	P Pc (C Cc)	00.3215%
5	P {N Nc} [F Fc]	00.0536%
5	P Pc {N} [F Fc]	00.0536%
5	P (C) {N} [F Fc]	00.0447%
5	P Pc (C) [F Fc]	00.0536%
5	P (C Cc) [F Fc]	00.0536%
5	P Pc {N Nc} [F]	00.0536%
5	P (C) {N Nc} [F]	00.0447%
5	P Pc (C) {N} [F]	00.0447%
5	P (C Cc) {N} [F]	00.0447%
5	P Pc (C Cc) [F]	00.0536%
5	P Pc (C) {N Nc}	00.0536%
5	P (C Cc) {N Nc}	00.0536%
5	P Pc (C Cc) {N}	00.0536%
6	P Pc {N Nc} [F Fc]	00.0107%
6	P (C) {N Nc} [F Fc]	00.0089%
6	P Pc (C) {N} [F Fc]	00.0089%
6	P (C Cc) {N} [F Fc]	00.0089%
6	P Pc (C Cc) [F Fc]	00.0107%
6	P Pc (C) {N Nc} [F]	00.0089%
6	P (C Cc) {N Nc} [F]	00.0089%
6	P Pc (C Cc) {N} [F]	00.0089%
6	P Pc (C Cc) {N Nc}	00.0107%
7	P Pc (C) {N Nc} [F Fc]	00.0018%
7	P (C Cc) {N Nc} [F Fc]	00.0018%
7	P Pc (C Cc) {N} [F Fc]	00.0018%
7	P Pc (C Cc) {N Nc} [F]	00.0018%
8	P Pc (C Cc) {N Nc} [F Fc]	00.0004%
		100.0000%

The odds of rolling a system with n number of stars is as follows:

Number of Star	Odds
1	48.2253%
2	33.7577%
3	13.6638%
4	03.5990%
5	00.6609%
6	00.0875%
7	00.0071%
8	00.0004%
	100.0018%

 

[aramis]

[FONT=arial,helvetica]NOTE: I just realized we have another set of parsing symbols if necessary: < >. These could be used for Companion Stars, if desired. [/FONT]

Using those breaks XML compatibility, so, no, they really are not available.

 

[tjoneslo]

Using those breaks XML compatibility, so, no, they really are not available.

They should be fine. The default T5SS data file is flat text. If you're going to put this data into an XML document you need to escape them. And if you're using XML storage format, you are no longer reading and editing by hand.

The other option is to use a marker like "+" to denote the close companion. E.g.
G1 V+M2 V

or the 8 star case becomes:

P+c (C+c) {N+c} [F+c]

or

O2 II+M2 V (G2 V+M1 V) {K4 V+M1 V} [F9 V+M9 V]

 

[maksimsmelchak]

Out of curiosity, I wanted to see what the odds were of rolling different stellar configurations in T5. There are 54 different types of possible systems:

Number of Stars	P	Odds
1	P	48.2253%
2	P [F]	08.0376%
2	P {N}	08.0376%
2	P Pc	09.6451%
2	P (C)	08.0376%
3	P [F Fc]	01.6075%
3	P {N} [F]	01.3396%
3	P Pc [F]	01.6075%
3	P (C) [F]	01.3396%
3	P {N Nc}	01.6075%
3	P Pc {N}	01.6075%
3	P (C) {N}	01.3396%
3	P Pc (C)	01.6075%
3	P (C Cc)	01.6075%
4	P {N} [F Fc]	00.2679%
4	P Pc [F Fc]	00.3215%
4	P (C) [F Fc]	00.2679%
4	P {N Nc} [F]	00.2679%
4	P Pc {N} [F]	00.2679%
4	P (C) {N} [F]	00.2233%
4	P Pc (C) [F]	00.2679%
4	P (C Cc) [F]	00.2679%
4	P Pc {N Nc}	00.3215%
4	P (C) {N Nc}	00.2679%
4	P Pc (C) {N}	00.2679%
4	P (C Cc) {N}	00.2679%
4	P Pc (C Cc)	00.3215%
5	P {N Nc} [F Fc]	00.0536%
5	P Pc {N} [F Fc]	00.0536%
5	P (C) {N} [F Fc]	00.0447%
5	P Pc (C) [F Fc]	00.0536%
5	P (C Cc) [F Fc]	00.0536%
5	P Pc {N Nc} [F]	00.0536%
5	P (C) {N Nc} [F]	00.0447%
5	P Pc (C) {N} [F]	00.0447%
5	P (C Cc) {N} [F]	00.0447%
5	P Pc (C Cc) [F]	00.0536%
5	P Pc (C) {N Nc}	00.0536%
5	P (C Cc) {N Nc}	00.0536%
5	P Pc (C Cc) {N}	00.0536%
6	P Pc {N Nc} [F Fc]	00.0107%
6	P (C) {N Nc} [F Fc]	00.0089%
6	P Pc (C) {N} [F Fc]	00.0089%
6	P (C Cc) {N} [F Fc]	00.0089%
6	P Pc (C Cc) [F Fc]	00.0107%
6	P Pc (C) {N Nc} [F]	00.0089%
6	P (C Cc) {N Nc} [F]	00.0089%
6	P Pc (C Cc) {N} [F]	00.0089%
6	P Pc (C Cc) {N Nc}	00.0107%
7	P Pc (C) {N Nc} [F Fc]	00.0018%
7	P (C Cc) {N Nc} [F Fc]	00.0018%
7	P Pc (C Cc) {N} [F Fc]	00.0018%
7	P Pc (C Cc) {N Nc} [F]	00.0018%
8	P Pc (C Cc) {N Nc} [F Fc]	00.0004%
		100.0000%

The odds of rolling a system with n number of stars is as follows:

Number of Star	Odds
1	48.2253%
2	33.7577%
3	13.6638%
4	03.5990%
5	00.6609%
6	00.0875%
7	00.0071%
8	00.0004%
	100.0018%

Fantastic work. I would love to see some larger-star configurations in T5SS.

The biggest I know of now is the six-star system rimward in Solomani space... The name is escaping me...

I also know of a 4-star system and plenty of trinaries and binaries... No 5-star systems though.

Shalom,
Maksim-Smelchak.

 

[whulorigan]

The biggest I know of now is the six-star system rimward in Solomani space... The name is escaping me...

Castor (2339 Solomani Rim)

 

[aramis]

They should be fine. The default T5SS data file is flat text. If you're going to put this data into an XML document you need to escape them. And if you're using XML storage format, you are no longer reading and editing by hand.

The other option is to use a marker like "+" to denote the close companion. E.g.
G1 V+M2 V

or the 8 star case becomes:

P+c (C+c) {N+c} [F+c]

or

O2 II+M2 V (G2 V+M1 V) {K4 V+M1 V} [F9 V+M9 V]

Most people I know don't read by hand; they use travellermap and expect it to be deciphered into readability.

Still, many others use XML. It's not like leaving out the <> really closes much off, and makes future uses much easier.

 

[tjoneslo]

Still, many others use XML. It's not like leaving out the <> really closes much off, and makes future uses much easier.

Can you point me to one or more XML uses for Traveller?

I know of a few attempts (including one of mine) but nothing in consistent use.

 

[maksimsmelchak]

Castor (2339 Solomani Rim)

Thanks, mate!

 

[aramis]

Several different attempts at system/sector mapping have been XML native file formats, with ability to import/export flat text files.

Everything in a standard application package on Android, Mac OS X, and iOS uses XML to some degree or another, since XML is part of how all three put together the application package. So, expect the next generation to start making more use of it.

Robject's webapps often use YAML, which is a subset of XML