Heaven & Earth Temperature Question

[Beck's]

Hi all!

I am currently creating some background for the campaign (CT, during the Psionic Suppressions) I am planning. Is is to begin in the Vilis-Subsector and I figured out the Rangent-System would be a good place to start the adventure (I need a low Tech planet where one of the PCs, a psionic, gets into trouble with some locals who form a mob and go after him...maybe I'll pick another place but that's not the issue here ). I am using Heaven & Earth to create the details of the Subsector's Systems and Worlds. It's a GREAT program and I don't know what I would be doing without it.

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WORLD DETAILS
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NAME: Rangent I Alpha

HEX LOCATION: 1411

UWP: E67A612-7

PBG: 503

TRADE CODES: Non-industrial, Water World

ALLEGIANCE: Non-aligned

STELLAR DETAILS: Primary Star: M4 V


Rangent I Alpha(Unknown: Unknown/1411)
E67A612-7 N Ni Wa 503 M4 V
G: 0,72 Day: 22,8 hrs Year: 54,448 days
Atmo: 1,2 Natural Weather
Temp: -90,771 (-73 to -133) (Season -57 to -190)
Agriculture; Agroproducts, Metals, Non-Metals; Recordings, Software, Documents
Reactionary/Stagnant; Competitive/Neutral; Harmonious/Xenophobic
Legal 2-22643, Tech 73-88778-7597-87-9

[...]

The atmosphere composition is a Standard oxygen-nitrogen mix, with low oxygen taint and the surface atmospheric pressure is 1,2 atm. The stellar luminosity is 0,32, the orbit factor is 836,345, the energy absorption is 0,619, the greenhouse effect is 1,1 and the base temperature is -90,771 degrees C. The orbital eccentricity temperature at closest approach is 0 degrees C and the orbital eccentricity temperature at furthest approach is 0 degrees C. The axial tilt base increase is 27,6 degrees C and the axial tilt base decrease is -46 degrees C. The length of day and night is 11,4 standard hours. The rotation luminosity factor is 0,32. The daytime rotation effects are 0,16 +per hour of daylight with an absolute maximum plus temperature of 145,784 degrees C. The nighttime rotation effects are 1,0 -per hour of darkness with an absolute maximum minus temperature of 27,334 degrees C. Native life exists. Atmospheric terraforming has not occurred. Greenhouse effect terraforming has not occurred. Albedo terraforming has not occurred.

[...]

TEMPERATURE WORKSHEET
---------------------

LATITUDE BASE
HEX BASE TEMPERATURE TEMPERATURE
ROW TEMPERATURE EFFECTS FOR HEX ROW
1 -91 18 -73
2 -91 12 -79
3 -91 6 -85
4 -91 0 -91
5 -91 -6 -97
6 -91 -12 -103
7 -91 -18 -109
8 -91 -24 -115
9 -91 -30 -121
10 -91 -36 -127
11 -91 -42 -133

AXIAL TILT HIGHEST
HEX SUMMER AXIAL TILT TEMP PLUS DAYTIME ORBIT ECC TEMP FOR
ROW PLUS FACTOR IN SUMMER PLUS PLUS HEX ROW
1 28 0,5 14 2 0,0 -57
2 28 0,75 21 2 0,0 -56
3 28 1 28 2 0,0 -55
4 28 1 28 2 0,0 -61
5 28 1 28 2 0,0 -67
6 28 1 28 2 0,0 -73
7 28 1 28 2 0,0 -79
8 28 1 28 2 0,0 -85
9 28 1 28 2 0,0 -91
10 28 1 28 2 0,0 -97
11 28 1 28 2 0,0 -103

AXIAL TILT LOWEST
HEX WINTER AXIAL TILT TEMP MINUS NIGHTTIME ORBIT ECC TEMP FOR
ROW MINUS FACTOR IN WINTER MINUS MINUS HEX ROW
1 -46 0,5 -23 11 0,0 -107
2 -46 0,75 -35 11 0,0 -125
3 -46 1 -46 11 0,0 -142
4 -46 1 -46 11 0,0 -148
5 -46 1 -46 11 0,0 -154
6 -46 1 -46 11 0,0 -160
7 -46 1 -46 11 0,0 -166
8 -46 1 -46 11 0,0 -172
9 -46 1 -46 11 0,0 -178
10 -46 1 -46 11 0,0 -184
11 -46 1 -46 11 0,0 -190

[...]


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Now my question: The map of the world, which is entirely white, suggests that the planet is just a gigantic ice-ball, that there never are plus temperatures. The temperature worksheet (sorry for the messed up tables) suggests the same. Why is it that there are plus temperatures in the text above? What's their meaning? Is it a bug? I've searched all forums, found several topic dealing with this program but I didn't find an answer.

The answer is probably very simple, some rule thingy I missed or something. Anyway, thanks in advance!

Regards,
Christopher Beckmann

 

[Malenfant]

I wondered what was up with the crazy temperatures til I realised you were using commas instead of decimal points...

You should realise that H&E is a bit buggy and the results should be checked. But that's what you're doing anyway .

There are several things I'm not sure about here:

1) The world should be tidelocked if it's that close to the star (0.2 AU, yes?). That would render your day and night modifiers somewhat irrelevant, since it has one face permanently towards the star and the other permanenting facing away from it. It also affects the temperature calculations too - it looks like you're using the WBH rules here, and I can't remember if they can account for tidelocking.

2) That being the case, it doesn't have an axial tilt.

3) if it's a gigantic iceball, it's very reflective. That means that the energy absorption should be a lot lower since the albedo is high. That would lower the temperature further.


Those are kinda beside the point perhaps, but I have no idea why your maximum daytime plus is so high. I think that's supposed to represent how high the temperature can possibly get, not how high the temperature really is.

Have you tried making the planet using the First In rules? They're more realistic and may avoid some of these problems.

 

[Beck's]

Originally posted by Malenfant:
I wondered what was up with the crazy temperatures til I realised you were using commas instead of decimal points...

[...]

Sorry, didn't think of that.

[...]There are several things I'm not sure about here:

1) The world should be tidelocked if it's that close to the star (0.2 AU, yes?). That would render your day and night modifiers somewhat irrelevant, since it has one face permanently towards the star and the other permanenting facing away from it. It also affects the temperature calculations too - it looks like you're using the WBH rules here, and I can't remember if they can account for tidelocking.

2) That being the case, it doesn't have an axial tilt.

3) if it's a gigantic iceball, it's very reflective. That means that the energy absorption should be a lot lower since the albedo is high. That would lower the temperature further.[...]

Hmm, Physics isn't a strength of mine. What's the probability for worlds to be tidelocked?

[...]Those are kinda beside the point perhaps, but I have no idea why your maximum daytime plus is so high. I think that's supposed to represent how high the temperature can possibly get, not how high the temperature really is.

Have you tried making the planet using the First In rules? They're more realistic and may avoid some of these problems.

Just did so a few times:

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WORLD DETAILS
-------------

NAME: Rangent I Beta

HEX LOCATION: 1411

UWP: E67A611-7

PBG: 503

TRADE CODES: Non-industrial, Water World

ALLEGIANCE: Non-aligned

STELLAR DETAILS: Primary Star: M4 V

SATELLITE DETAILS: Number: 1
Satellite 1: UWP:Y100000-0, Orbit: 50


Rangent I Beta(Unknown: Unknown/1411)
E67A611-7 N Ni Wa 503 M4 V
G: 0.377 Day: 0.625 standard days Year: 1.667 standard years
Atmo: 0.565 Temp: 231.396
Low (-3);High (+3);Low (-3);Low (-3);High (+2);Moderate (0);Moderate (0);Low (-2);
Legal 1-1000, Tech 72-787787-322


The world diameter is 5,700 miles. The density is 2.9 g/cc or 0.527 Earth standard. The world mass 0.195 Earth masses. The surface gravity is 0.377 G.

The orbital eccentricity is 0.08, the minimum separation is 0.92, the maximum separation is 1.08. The orbital period is 1.667 standard years (608.779 standard days). The tidal force (from primary star) is 0.117, the total tidal effect is 45.702. The rotation period is 0.625 standard days. The day length is 0.625 standard days. The axial tilt is 45 degrees.

The corrected size parameter is 0.272 (Small). The world is Desert.

The atmospheric pressure is 0.565 atmospheres (Thin).

There are no land masses.

There is No life.

The atmospheric composition is Exotic.

The albedo factor is 0.28. The greenhouse factor 0.0. The blackbody temperature 241.095 K, the average suface temperature is 231.396 K (-43.488 degrees F). Frigid.

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Alright. The temperature here seems to be given in Kelvin (May this have been the case in the first example as well?). 231 K would be -42°C. The map is all blue, so no ice (assuming the white map from our previous example wasn't just a bug). Yet it's frigid. And..."The world is Desert.". Hard to decide...

 

[Malenfant]

Originally posted by Christopher:
Hmm, Physics isn't a strength of mine. What's the probability for worlds to be tidelocked?

Generally, if a world is within about 0.5 AU of any star, the probablity is about 100%

.

Alright. The temperature here seems to be given in Kelvin (May this have been the case in the first example as well?). 231 K would be -42°C. The map is all blue, so no ice (assuming the white map from our previous example wasn't just a bug). Yet it's frigid. And..."The world is Desert.". Hard to decide...

Hm. Sounds like H&E is very buggy indeed here. You've now got atm 7, but it claims the atmosphere is exotic? Plus it's now around 1 AU from the star? And it thinks it's a desert world despite having hydrographics of A??

This doesn't really seem to be making any sense at all...

 

[daryen]

One thing I have found H&E to do is use absolutely fixed orbit distances. So, in this case, orbit 1 (or is it 0?) is always 0.2 AU. In that case, the star may be too faint to warm the planet sufficiently.

What I always did, since I can't fiddle with the orbit distance, was to fiddle with the star size. Move the size up or down to get the base temperature you want, then use that data. I figured that as long as the star sizes were reasonably close in size, the "0.2AU" really meant "0.149872346AU" (or whatever the real number would work out to be).

As for the wonky data in your last run, I don't know. I would double check your input data, blow away the first results, and try again.

 

[BrennanHawkwood]

Originally posted by Christopher:


The daytime rotation effects are 0,16 +per hour of daylight with an absolute maximum plus temperature of 145,784 degrees C. The nighttime rotation effects are 1,0 -per hour of darkness with an absolute maximum minus temperature of 27,334 degrees C.

<SNIP>

Now my question: The map of the world, which is entirely white, suggests that the planet is just a gigantic ice-ball, that there never are plus temperatures. The temperature worksheet (sorry for the messed up tables) suggests the same. Why is it that there are plus temperatures in the text above? What's their meaning? Is it a bug? I've searched all forums, found several topic dealing with this program but I didn't find an answer.

IIRC, the absolute max temperature modifiers are calculated with a formula based on the various factor that influence the base temperature and are kind of the "max that could be added or subtracted if the day never ended or night never ended". The actual number added or subrtracted from the temperature is the small modifier * length of day or night. Those huge numbers are just limits to how big a number can be calculated. On th other hand, the numbers do look a rather large.

 

[BrennanHawkwood]

Originally posted by Christopher:
WORLD DETAILS
-------------
Rangent I Beta(Unknown: Unknown/1411)
E67A611-7 N Ni Wa 503 M4 V
G: 0.377 Day: 0.625 standard days Year: 1.667 standard years
Atmo: 0.565 Temp: 231.396
Low (-3);High (+3);Low (-3);Low (-3);High (+2);Moderate (0);Moderate (0);Low (-2);
Legal 1-1000, Tech 72-787787-322


The world diameter is 5,700 miles. The density is 2.9 g/cc or 0.527 Earth standard. The world mass 0.195 Earth masses. The surface gravity is 0.377 G.

The orbital eccentricity is 0.08, the minimum separation is 0.92, the maximum separation is 1.08. The orbital period is 1.667 standard years (608.779 standard days). The tidal force (from primary star) is 0.117, the total tidal effect is 45.702. The rotation period is 0.625 standard days. The day length is 0.625 standard days. The axial tilt is 45 degrees.

The corrected size parameter is 0.272 (Small). The world is Desert.

The atmospheric pressure is 0.565 atmospheres (Thin).

There are no land masses.

There is No life.

The atmospheric composition is Exotic.

The albedo factor is 0.28. The greenhouse factor 0.0. The blackbody temperature 241.095 K, the average suface temperature is 231.396 K (-43.488 degrees F). Frigid.

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Alright. The temperature here seems to be given in Kelvin (May this have been the case in the first example as well?). 231 K would be -42°C. The map is all blue, so no ice (assuming the white map from our previous example wasn't just a bug). Yet it's frigid. And..."The world is Desert.". Hard to decide...

Some of the oddities with this round of generation come from using a pre-exisitng UWP with the GT:First In system which tends to be more 'realistic' (as in, it tends to result in fewer outright unrealistic worlds) than many of the other Traveller world gen systems. For instance, GT:FI ties atmosphere type and climate more closely with world size than the default generation system in H&E.

In this case, the world is too small to retain water vapor in its atmosphere. That is what the world type of DESERT means. It is no indicator of temperature. Using GT:First In terms the world type for Mars is on the borderline between Desert and Rockball.

The atmospheric pressure is low because the gravity is so low. That is calculated by a rolling a random factor and multiplying it by the planet's gravity. Based on average rolls, that is actually a higher than likely atmospheric pressure for that planet based on GT:FI generation (ie. the program 'rolled' a 15 on 3D6 to get that result).

(A side note, if I am reading the modifiers correctly the highest hydrographic percentage this world could have had if generated originially by GT:FI would be 60% and an average roll would have produced a 0-10% hydrographic percentage.)

The 'No Life' result would have been a random roll and would then have an impact on atmospheric composition. GT:FI uses the model that a planet cannot have an earthlink atmosphere without life to support it. Therefore, as a result of the lack of life and the Desert type, the atmosphere is assumed to be mostly nitrogen with smattering of other gases such as carbon dioxide, nitrogen oxide, argon and so on. This is a non-corrosive, non-breathable atmosphere, which qualifies it as 'Exotic'.

Not sure why the map shows all blue. IIRC from my playing around with H&E the mapping feature did not work very well with the GT:FI generation system. With an average climate of frigid and a 100% hydrographic percentage I would say the 'polar' ice caps pretty much cover the planet. There could well be liquid water under the ice, but I doubt there is much on the suface. I would also say that the all white map you got originally would have been acurate to the data generated (further application of real world planetology aside) simply because the planet is really cold.

 

[Malenfant]

Originally posted by BrennanHawkwood:
Some of the oddities with this round of generation come from using a pre-exisitng UWP with the GT:First In system which tends to be more 'realistic' (as in, it tends to result in fewer outright unrealistic worlds) than many of the other Traveller world gen systems. For instance, GT:FI ties atmosphere type and climate more closely with world size than the default generation system in H&E.

Though in this case the UWP is actually fairly reasonable from a realism POV (though the star type isn't. I find it hard to imagine how a tide-locked waterworld could work).

In this case, the world is too small to retain water vapor in its atmosphere.

That's because the density is rather low - only 2900 kg/m3. Actually, that means there's a significant amount of ice making up the world's mass. That implies that it was a large Europa-like world that formed in the outer zone and wandered into the inner system somehow. It's stretching it a bit, but if that's the case then it could have happened within the past million years or so and it could be that the world IS currently in the process of losing all its water.

One obvious solution to this would be to increase the density to something more like Earth's (around 5000 kg/m3). Then it'd be quite capable of retaining water. (and it would have formed in situ and would be entirely rocky crust/mantle and iron core)

(A side note, if I am reading the modifiers correctly the highest hydrographic percentage this world could have had if generated originially by GT:FI would be 60% and an average roll would have produced a 0-10% hydrographic percentage.)

Using the UWP generation system, a size 6 world could have a hydrographics of A. You roll an 11 or 12 on the 2d-7 roll, and add the world size to get A.

I can't remember (I don't have the book right in front of me), doesn't FI have a straight 2d-2 kinda roll with a few modifers for hydrographics?

The 'No Life' result would have been a random roll and would then have an impact on atmospheric composition. GT:FI uses the model that a planet cannot have an earthlink atmosphere without life to support it. Therefore, as a result of the lack of life and the Desert type, the atmosphere is assumed to be mostly nitrogen with smattering of other gases such as carbon dioxide, nitrogen oxide, argon and so on. This is a non-corrosive, non-breathable atmosphere, which qualifies it as 'Exotic'.

Though given the UWP, and the hydrographics of A, it seems a bit odd that there'd be no oxygen in the atmosphere. Maybe the world is a young one, and aerobic bacteria haven't formed in its world ocean yet?

With an average climate of frigid and a 100% hydrographic percentage I would say the 'polar' ice caps pretty much cover the planet. There could well be liquid water under the ice, but I doubt there is much on the suface. I would also say that the all white map you got originally would have been acurate to the data generated (further application of real world planetology aside) simply because the planet is really cold.

Though that wouldn't count as hydrographics A then. The hydrographics is specifically the percentage of liquid exposed on the surface, not underneath it.

 

[Malenfant]

Or, put it another way, I think that to get a world with a physical UWP of 67A, it needs to have about Earthlike density (to hold onto its water), and be in the habitable zone of a star that is between late F V and early K V (so it isn't tidelocked). It may also be rather young or have unusually deep oceans, since continents haven't formed yet

 

[daryen]

To expand the discussion a tad, I had been told by others that a tidelocked world can have a breathable atmosphere. Isn't that the case? If so, then shouldn't even a tidelocked world be able to have oceans?

Oh, and historically, hydrographic percentage includes surface ice. So, a partially frozen water world is still hydro A, even if only (say) half of it is liquid. (I don't know if that is different in GT or not, but in CT and MT, at least, a frozen world completely covered in ice is hydrographics A.)

 

[Malenfant]

A tidelocked world can have a stable atmosphere, yes. And it can have oceans too. The problem is, that if the dayside goes above the boiling point of water (at that atmospheric pressure), then it should all evaporate and redeposit onto the dark side. If that's the case, you can't have a tidelocked world that is entirely covered with oceans.

I think you're wrong about the hydrographics though. First, the definition of the hyd digit in book 3 explicitly says says that it respresents "the percentage of liquid exposed on the surface". Second, according to book 6 all the icy bodies in the solar system (Europa, Ganymede, etc) have hydrographics of 0. That tallies with the definition in book 3 - they have water under their ice shells, but none of it is exposed as liquid on the surface.

 

[BrennanHawkwood]

Originally posted by Malenfant:
</font><blockquote>quote:</font><hr />Originally posted by BrennanHawkwood:
In this case, the world is too small to retain water vapor in its atmosphere.

That's because the density is rather low - only 2900 kg/m3. Actually, that means there's a significant amount of ice making up the world's mass. That implies that it was a large Europa-like world that formed in the outer zone and wandered into the inner system somehow. It's stretching it a bit, but if that's the case then it could have happened within the past million years or so and it could be that the world IS currently in the process of losing all its water.

One obvious solution to this would be to increase the density to something more like Earth's (around 5000 kg/m3). Then it'd be quite capable of retaining water. (and it would have formed in situ and would be entirely rocky crust/mantle and iron core)
</font>[/QUOTE]Yeah, I had noticed the really low density...I guess I over simplified with the reference to it being too 'small'. You are absolutely right that increasing the density would make a big difference. Using GT:FI's formulas, increasing the world's density by as little as 1.25 g/cc (increasing it to 4.15g/cc and shifting it from a silicate world to a low iron world) would change its corrected size parameter to the minimum value for a standard world, thus allowing it to retain water vapor. It would also increase the gravity to 0.54g and if using the same 'rolls' as before the atmospheric pressure would increase to 0.81 atmospheres (which is just barely a standard atmosphere by GT:FI rules).

Originally posted by Malenfant:

</font><blockquote>quote:</font><hr />Originally posted by BrennanHawkwood:
(A side note, if I am reading the modifiers correctly the highest hydrographic percentage this world could have had if generated originially by GT:FI would be 60% and an average roll would have produced a 0-10% hydrographic percentage.)

Using the UWP generation system, a size 6 world could have a hydrographics of A. You roll an 11 or 12 on the 2d-7 roll, and add the world size to get A.

I can't remember (I don't have the book right in front of me), doesn't FI have a straight 2d-2 kinda roll with a few modifers for hydrographics?
</font>[/QUOTE]Yep. The roll boils down to a 2d6-2 with negative modifiers for stars of type F and A, desert worlds and hostile worlds. There are slight positive modifiers for type M and K stars. In this case, if the hydro score had been rolled according to GT:FI rather than pre-specified it would have been a 2d-2 roll, +2 for type M star, -8 for desert world in Life Zone (assumed) so a total of 2d-8 which could produce a hydrographic percentage between 0 and ~40% with an average roll producing 0%. (Guess I screwed up the math the first time... )

Originally posted by Malenfant:

</font><blockquote>quote:</font><hr />Originally posted by BrennanHawkwood:
The 'No Life' result would have been a random roll and would then have an impact on atmospheric composition. GT:FI uses the model that a planet cannot have an earthlink atmosphere without life to support it. Therefore, as a result of the lack of life and the Desert type, the atmosphere is assumed to be mostly nitrogen with smattering of other gases such as carbon dioxide, nitrogen oxide, argon and so on. This is a non-corrosive, non-breathable atmosphere, which qualifies it as 'Exotic'.

Though given the UWP, and the hydrographics of A, it seems a bit odd that there'd be no oxygen in the atmosphere. Maybe the world is a young one, and aerobic bacteria haven't formed in its world ocean yet?
</font>[/QUOTE]True, given the pre-existing UWP I agree completely. This is a good example of why it is useful to know the generation system so you know where things need to be tweaked to make things fit better. A big one with this world is the world's density as determined randomly by the program. Increasing that one stat makes a huge difference in the world's environment.

Originally posted by Malenfant:


</font><blockquote>quote:</font><hr />Originally posted by BrennanHawkwood:
With an average climate of frigid and a 100% hydrographic percentage I would say the 'polar' ice caps pretty much cover the planet. There could well be liquid water under the ice, but I doubt there is much on the suface. I would also say that the all white map you got originally would have been acurate to the data generated (further application of real world planetology aside) simply because the planet is really cold.

Though that wouldn't count as hydrographics A then. The hydrographics is specifically the percentage of liquid exposed on the surface, not underneath it. </font>[/QUOTE]I think there is some wiggle room there...though I agree an entirely ice covered world might be pushing too far. If this world was IMTU I might go with the world spanning ice cap, but I'd definately stipulate that it is a thin layer of ice over extensive liquid oceans.

Actually, I just noticed another little issue with this world that makes or breaks the UWP. I had been assuming it was in the life zone of its star (partly because I usually don't bother with most of the temperature stuff for worlds that aren't). Looking back at the GT:FI based version of the planet the world is orbiting between 0.92 and 1.08 AU around a M4 V star. Looking at the Obital Zones Table, it would appear that this world is not in the Life Zone at all and may well be out past the Snow Line.

That could well explain the low density since worlds outside the snow line start at a much lower value when calculating density. The world type should also be a Hostile ammonia world (kind of like Titan) which would end up with a corrosive atmosphere. Definately not a match with the provided UWP.

 

[BrennanHawkwood]

Originally posted by Malenfant:
Or, put it another way, I think that to get a world with a physical UWP of 67A, it needs to have about Earthlike density (to hold onto its water), and be in the habitable zone of a star that is between late F V and early K V (so it isn't tidelocked). It may also be rather young or have unusually deep oceans, since continents haven't formed yet

Absolutely. The base UWP fails these tests where the star is concerned, though depending on how tidal locking is handled, careful attention to the other details (density, orbital distance, etc.) and ideas like the deep oceans and so on could make the UWP workable.

 

[BrennanHawkwood]

Originally posted by daryen:
To expand the discussion a tad, I had been told by others that a tidelocked world can have a breathable atmosphere. Isn't that the case? If so, then shouldn't even a tidelocked world be able to have oceans?

Oh, and historically, hydrographic percentage includes surface ice. So, a partially frozen water world is still hydro A, even if only (say) half of it is liquid. (I don't know if that is different in GT or not, but in CT and MT, at least, a frozen world completely covered in ice is hydrographics A.)

It looks like a tidelocked world with liquid oceans is possible using GT:FI, just not probable. For tidelocked worlds, GT:FI modifies several of the world generation steps (pg.62). In summary, they tend to have minimal axial tilt, the size parameter used to determine world type is half that of an equal non-tide locked world (making it much less likely that the world can retain a breathable atmosphere or water). If the world can have a hydrosphere there is a siginificant penatly to the roll and the final average surface temperature is warmer than usual.

Looking at GT:FI, the hydrographics section refers to 'extensive oceans of some liquid substance' and 'percentage of surface covered by liquid'. Could be taken as implying exposed liquid oceans, but I don't think it outright excludes the occasional ocean covered by a sheet of ice...

(In the mapping section it is mentioned that Ocean worlds can have permanent ice cover near the poles and gives a guideline minimal climate level for determining how far from the pole these regions should extend. It does mention the possibility of warm ocean currents preventing ice cap from forming over water hexes but does not require it.)

 

[Antony]

If the eccentricity was increased to 0.15 then you could have a resonant tidal lock giving the world a rotation period of 2/3rds its orbital period. Temperatures are then calculated normally for the rotation period without worrying about a full tidal lock.

Another thing you could try is having the world orbit a gas giant at the distance you want from the primary star. The "world" is then a moon tidally locked to the gas giant (but not to the primary). Since gas giants have been discovered in very close orbits this should not be a problem.

Incidently the tidal stresses on such a "world" would give it a great deal of shall we say seismic activity and could generate sufficient heat by stress (look at Io) to keep any water liquid.

 

[Malenfant]

Another thing you could try is having the world orbit a gas giant at the distance you want from the primary star. The "world" is then a moon tidally locked to the gas giant (but not to the primary). Since gas giants have been discovered in very close orbits this should not be a problem.

There's a problem with that - while the gas giant may not be tidelocked (they're take a hell of a lot longer to become locked to the star even if they're that close), the solar tides will directly act on the satellites themselves, which will rapidly break up any satellite systems. I'm not entirely sure how - the tides will either cause the satellites to be pushed away (in which case they become independent bodies orbiting the star) or pulled into the gas giants (in which case the satellites are destroyed).

 

[Beck's]

Well, thanks for the replies and clarifications!

I'll go with the advice to play around with the primary star a bit to get more believable temperatures. Plus a tidelocked waterworld wouldn't work anyway as I understand it. I wasn't aware of tidally locked worlds before...I think I'll bring them in somewhere else. They sure make for an interesting adventuring environment.