T5 Web Apps

[cym0k]

Yep. I see it now. The T5 book, web app, and examples through out all go for W/A/S. The bulleted contents list on the Survey documentation needs tweaking.

How the hell did I get my brain mixed up in all that? I do apologise.

"we have normality, I repeat we have normality.Anything you still can’t cope with is therefore your own problem."

 

[thalassogen]

No need to apologize!

 

[Lycanorukke]

The documentation just states that, too. I may be blind for my own mistakes, though. Where does a mixture of CT and T5 occur?

My bad.

The 'N' ( world number) appears right where the base code appears in CT, and N is 'naval base'. This may be why they use integers rather than eHex.

Also looking again, I think a 'green TAS' is a simple dash (no code as opposed to R or A), and I checked the 2nd survey page as well to confirm- "Worlds given a Green Zone rating are usually indicated by leaving the data field blank or - (dash)."

However as it has a dash followed by a 'G' where G is a base in the Travmap (the only bases in the book are N,D,S,W), I assumed the base 'G' was placed _after_ the TAS code by mistake.

 

[thalassogen]

Ah, I see! I'll change the G in Z to a dash. Thanks for the explanation.

 

[inexorabletash]

The TravellerMap docu page shows a correct example World/Allegiance/Stellar, but the bullets under "Contents" change that order to Allegiance/World/Stellar. That's the glitch, I think.

Fixed, sorry. The Table of Contents still had the classic ordering.

Still, I have no idea why W (number of worlds) should use decimals...

Sadly, the BBB's example is ambiguous. Marc's T5SS spreadsheet that I use as source data had that field as decimal, which is why I have it as decimal. I should make my parser handle either.

 

[whulorigan]

Stellar Luminosity Table - TravellerMap

http://travellermap.com/doc/secondsurvey.html might be useful

I am looking over the webpage above on TravellerMap, and I am not sure if I am in error regarding T⁵ stellar-classification notation, or if there is an error in the text on the page.

Toward the bottom of the page is the Stellar Data section, where it is stated:

"The size code D may be used for dwarf stars, for example MD for a red dwarf; the special code BD is used for brown dwarf objects (failed stars) and WD is used for white dwarfs (hot stellar remnants). If the D code is used the spectral decimal is omitted."

The Stellar Luminosity Table is as follows [I have omitted the stellar diameter column]) :

Stellar Luminosity

The luminosity gives the magnitude, or brightness of the star. This correlates with the size of the star, although it varies depending on spectral class.

Code	Description
Ia	Bright Supergiant
Ib	Weak Supergiant
II	Bright Giant
III	Normal Giant
IV	Subgiant
V	Main Sequence Star
VI	Subdwarf (NOTE: Use D instead)
VII	White Dwarf (NOTE: Use WD instead)
D	Dwarf

My question is about the Type VI, Type VII, and Type D Codes.

In the T⁵ Core Rulebook p.436, "D" in that table is clearly being used to denote a White (Degenerate) Dwarf Star exclusively, and is the same thing as a Type VII Star (in the TravellerMap Table: WD).

The table above, OTOH, seems to imply that D is being used for Sub-Dwarf (Type VI or "sd"-Type) Stars (see row). But this is ambiguous, as there is also an independent row for D, simply entitled "Dwarf".

In general, the use of "Dwarf" for stars can mean any of the following:

1) Any "Main-Sequence" (Type V) Star (which used to be called a Dwarf Star, though the term is now only commonly employed for Red Main-Sequence Stars (e.g. "Red-Dwarfs");

2) A "Sub-Dwarf" (Type VI or "sd"-Type) star, which is smaller and less luminous (though similar to) a Main-Sequence (Dwarf) Star, as above;

3) A "Brown Dwarf", which in T⁵ has the clear notification "BD", as also noted on the TravellerMap page;

4) A White (Degenerate) Dwarf (Type VII) star (also WD in the TravellerMap table), which is the dead, glowing cinder of a former star.

​

Is the notation for "D" as used by the TravellerMap text above simply a generic note that any star with "Dwarf" in its name can use some version of the "D" notification? The reason that I ask is that Traveller thru its various editions has had a well-known history of having anomalously high numbers of White Dwarfs generated by its star-system generators, and has had various people propose schemes to fix the problem in the published data. Based on the codes above, I am not quite sure what to make of the various "Dwarf" type stars (particularly points #1, #2, and #4 above), and what they are intended to represent by the code.

So where the TravellerMap page quote says: [FONT=arial,helvetica]"The size code D may be used for dwarf stars, for example MD for a red dwarf . . . " - In this case "D" is representing a Main-Sequence (Type V) star (which would have a decimal-spectral number).

In the [/FONT][FONT=arial,helvetica]TravellerMap table above, "D" is specifically noted as being the notation for a Type VI Subdwarf.
[/FONT]
[FONT=arial,helvetica]In the T5 Core Rulebook (p.436), "D" is (I believe) being used to specifically denote a White (Degenerate) Dwarf Star, which is the same thing as a Type VII Star (labelled in your table as WD).


Could you provide some clarification?





[/FONT]

 

[whulorigan]

Stellar Luminosity Table - TravellerMap (continued)

As an example from TravellerMap:

Prometheus in the Solomani Rim is a world in the Alpha Centauri Star System.
Its TravellerMap stellar-data is:

SolomaniRim-2027 Prometheus G2V K1V M5V

The M5V component is Proxima Centauri, which is an M5.5 Red Dwarf, and is correctly noted in the above data as a Main Sequence (Type V) Dwarf star. Note that it is not labelled "MD".

 

[thalassogen]

D normally denotes White Dwarves, i.e. stellar remnants. Adding a spectral class to this accounts for the dead star's surface heat, but that information is of no real use, e.g. BD is a white-blue (temperature-wise) white dwarf stellar remnant, hence the unsuitability of BD to denote a Brown Dwarf.

Sub Dwarf (VI) stars are most likely Main-Sequence (V) aka dwarf stars with very low metallicity and thereby lower diameter and a hotter surface, resulting in a lower mass/smaller star shining brighter than expected.

A Red Dwarf star is really a very low mass V or VI star.

A Brown Dwarf is a something too light to become a real star and too massive to be considered a mere Jupiter. BTW, there are spectral classes for very low mass red dwarf stars and brown dwarves that account for their low temperature, those are L, T, and Y (all below M).

All this I listed at http://www.heldenhaufen.de/Va/Worldbuilding/Documentation (scroll down to "Classification of Stars").

 

[Original_Carl]

My favorite resource for Stellar Classification:

http://en.wikipedia.org/wiki/Stellar_classification

 

[whulorigan]

D normally denotes White Dwarves, i.e. stellar remnants. Adding a spectral class to this accounts for the dead star's surface heat, but that information is of no real use, e.g. BD is a white-blue (temperature-wise) white dwarf stellar remnant, hence the unsuitability of BD to denote a Brown Dwarf.

Sub Dwarf (VI) stars are most likely Main-Sequence (V) aka dwarf stars with very low metallicity and thereby lower diameter and a hotter surface, resulting in a lower mass/smaller star shining brighter than expected.

A Red Dwarf star is really a very low mass V or VI star.

A Brown Dwarf is a something too light to become a real star and too massive to be considered a mere Jupiter. BTW, there are spectral classes for very low mass red dwarf stars and brown dwarves that account for their low temperature, those are L, T, and Y (all below M).

All this I listed at http://www.heldenhaufen.de/Va/Worldbuilding/Documentation (scroll down to "Classification of Stars").

Yes, I am aware of the Astrophysics. My question is how is the code to be interpreted on the TravellerMap website? The Code "D" appears in two different places on the following page under the stellar type section (as I detailed in my post):
http://travellermap.com/doc/secondsurvey.html

The TravellerMap table on the above-referenced page variously uses "D" for Subdwarf (Type VI) and "Dwarf" (generic). And T⁵ (which the TravellerMap data is supposed to show) uses "D" for White Dwarfs. Those objects are very different, as you have noted above in your post.

Most earlier editions of Traveller generate a HUGE number of White Dwarfs as stellar companions (according to their various rulesets and associated extended UWP data), and some people (MJD among others in his published works) have attempted to rectify this anomaly by retconning the data to better reflect reality (usually by making all of those "M_D" type "white dwarfs" in to "M_V" Red Dwarfs. *

* - In reality, only about 6% of stars observed are White Dwarfs (about one in twenty), whereas the MAJORITY of companion stars in earlier rulesets were White Dwarfs. Also, about 75-80% of observed stars in the sky are Red Main-Sequence Dwarfs.
​

My question essentially is: If I come across a star labelled "D" (or DM, or MD, or M3D, etc) on TravellerMap, does that mean it is supposed to be a Red Dwarf, a Red Subdwarf, or a White Dwarf with essentially meaningless surface-temperature data appended? Does the table on the TravellerMap website need to be updated/corrected (or at least clarified)?


Example #1:

For example, look at Sirius in the Dingir Subsector on TravellerMap:

SolomaniRim 1621 Sirius A1V A2D

​

Sirius in reality is an A1V star orbited by a White Dwarf companion (the A2D listed above). If I did not know from Astronomy that Sirius was orbited by a White Dwarf companion, how would I interpret the above data based on the TravellerMap page above? Is it an "A-Subdwarf" or an "A-White Dwarf?


Example #2:

If I look at Meshan (@ Epsilon Indi):

SolomaniRim 1526 Meshan K5V M1D M6D

​

We have an Orange K5V Main Sequence Dwarf-Star orbited by . . .

a) Two Red Dwarfs (M1D & M6D)?
b) Two Red Subdwarfs (M1D & M6D)?
c) Two White Dwarfs with meaningless surface-temperature data (M1D & M6D)?
​

Answer: It is unclear from the TravellerMap page which of the above three is meant.

Real World Answer: d) - They are two Brown Dwarfs (T1V & T6V)

Do you see what I mean? The stellar code data needs to be made consistent & clarified.

 

[thalassogen]

Do you see what I mean? The stellar code data needs to be made consistent & clarified.

I see. And I agree with you. I guess inexorabletash will answer to this as soon has he reads up here. But maybe you want to PM him directly.

 

[inexorabletash]

Quoting the page, which is a synthesis of T5 and legacy data:

"The size code D may be used for dwarf stars, for example MD for a red dwarf; the special code BD is used for brown dwarf objects (failed stars) and WD is used for white dwarfs (hot stellar remnants). If the D code is used the spectral decimal is omitted."

Obviously, the spectral decimal is not always omitted. But a white dwarf should be WD and nothing else should be a white dwarf. Is the page ambiguous?

I'll check what the T5 BBB says when I get home.

 

[whulorigan]

Quoting the page, which is a synthesis of T5 and legacy data:

"The size code D may be used for dwarf stars, for example MD for a red dwarf; the special code BD is used for brown dwarf objects (failed stars) and WD is used for white dwarfs (hot stellar remnants). If the D code is used the spectral decimal is omitted."

Obviously, the spectral decimal is not always omitted. But a white dwarf should be WD and nothing else should be a white dwarf. Is the page ambiguous?

I'll check what the T5 BBB says when I get home.

The table in that section also has a note beside "Type VI - Subdwarf" that says: "Note: Use "D" instead", and besdie Type VII - White Dwarf that says "Note: Use "WD" instead". But "D" in the UWP data for the system details seems to refer to White Dwarfs.

Also, Red Dwarfs are actually Red Main-Sequence Stars (Type V). So, for example, M3D would be ambiguous if MD refers to "Red Dwarfs". If it is a Red Dwarf, it should be M3V. If it is a subdwarf, it should be M3VI.

In the specific example of Meshan that I gave (where it is canonically known that the world is orbiting the star Epsilon Indi), the system should be K5V BD BD, not K5V M1D M6D.

 

[inexorabletash]

Okay, to clarify:

T5 itself doesn't contain definitions for stars; it assumes you know the Yerkes (a.k.a. Morgan–Keenan) classification scheme, which is to say a mix of spectral type OBAFGKM plus a decimal (i.e. G9 is almost a K0) and size Ia,Ib,II,III,IV,V,VI, with these extensions: If size = D, ignore spectral decimal. If Spectral = BD (=Brown Dwarf), ignore remaining rolls. This is on page 436 of the BBB.

So per T5, you can have:

(O | B | A | F | G | K | M ) ( 0 ... 9 ) ( Ia | Ib | II | III | IV | V | VI )

or:

(O | B | A | F | G | K | M ) D

or:

BD

So that's the rules. Now toss in history. There used to be VII for white dwarf. This is seen in the Challenge #26 data format documentation http://localhost/~josh/travellermap/doc/trader_format.html - also seen in CT Book 6. Book 6 also lists different white dwarf spectra on page 45: DB DA DF DG DK DM. None of those are found in the T5 data.

What is found in the T5 data is an additional code: WD. T5 data also contains dwarfs with spectral decimal, e.g. the A2D in Sirius.

If you look at legacy data files, though, you'll find all of the above, plus the occasional lone D - not sure what that means - and an explicit Un for Unknown.

Re: http://travellermap.com/doc/secondsurvey.html#stellar

* I'm not sure where the "Subdwarf. NOTE: Use D instead." detail came from. I'll remove it.
* I'll clarify that BD and WD are the whole code, not just size.

 

[inexorabletash]

But "D" in the UWP data for the system details seems to refer to White Dwarfs.

Not in the T5 data, although the T5 data may disagree with reality.

Also, Red Dwarfs are actually Red Main-Sequence Stars (Type V). So, for example, M3D would be ambiguous if MD refers to "Red Dwarfs". If it is a Red Dwarf, it should be M3V. If it is a subdwarf, it should be M3VI.

In reality, perhaps, but not in Traveller.

EDIT: To clarify - I don't know what the difference between M0 V, M0 VI and MD is supposed to be in Traveller, but they are apparently distinct kinds of stars in the universe described by the T5 rules.

In the specific example of Meshan that I gave (where it is canonically known that the world is orbiting the star Epsilon Indi), the system should be K5V BD BD, not K5V M1D M6D.

The Traveller universe may not match the real universe; alternately, the IISS makes mistakes and the Second Survey data can be corrected. Contact DonM.

 

[whulorigan]

EDIT: To clarify - I don't know what the difference between M0 V, M0 VI and MD is supposed to be in Traveller, but they are apparently distinct kinds of stars in the universe described by the T5 rules.

M0V = Red Main Sequence (Dwarf) Star
M0VI = Red Subdwarf
MD ==> Presumably a White Dwarf (one with a failry cool surface temperature).

(At least, w/o specific further clarification, that is what I would have to conclude or extrapolate based on standard usage in Astrophysics).

 

[inexorabletash]

Some stats in the T5SS data. First, the easy ones:

* 1 systems with size 1b star (Antares)
* 1 systems with size Ia star (Deneb)
* 56 systems with size II stars
* 252 systems with size III stars
* 221 systems with size IV stars
* 12523 systems with size V stars

Now the pesky ones:

* Only 1 VI star (Hentor)
* No VII stars
* Only 2 MD stars (both in the Spinward Marches)
* 13 M#D stars, most in Hinterworlds or Solomani Rim
* 2 K#D, 2 A#D, 1 F#D
* No AD, FD, GD, or KD.
* One BD star (Claverse)
* 55 WD stars
* Only 1 D star - i.e. only D, nothing else (Luuru)

* 5 RD (?!?) - that's a new one!

 

[whulorigan]

What is found in the T5 data is an additional code: WD.

Can you point me to where this code is used? I have looked at p.436 in T⁵ several times and can find no mention of a "WD" classification for stars. Maybe I am just tired and missing it.

EDIT: OK I am getting tired. You meant that the T5SS Data includes the code "WD" in various places, not that the code is found in the T5 Core Rulebook.

 

[whulorigan]

* Only 1 D star - i.e. only D, nothing else (Luuru)

That might be legacy from GT:Rim of Fire perhaps? GT used just a "D" for White Dwarfs.

 

[aramis]

Not in the T5 data, although the T5 data may disagree with reality.



In reality, perhaps, but not in Traveller.

EDIT: To clarify - I don't know what the difference between M0 V, M0 VI and MD is supposed to be in Traveller, but they are apparently distinct kinds of stars in the universe described by the T5 rules.



The Traveller universe may not match the real universe; alternately, the IISS makes mistakes and the Second Survey data can be corrected. Contact DonM.

Yerkes type VI are, as far as i can tell, low metalicity low initial helium main sequence stars.
On the HR diagram, they're a parallel line, and only exist in the G5-M5 spectra.

Type VII are "white dwarves" in the O7 (or so) to K5 range. The remnants of dead main sequence stars below the black hole threshhold.