100 Diameters of Stars???

[Badbru]

I'd like to start useing the jump shadow/masking effects of stars for jumping into systems.

My problem is thus, unless I'm blind I can't see any reference to Star type Diameter's in my copy of either TNE Rules book or World Tamers Handbook.

Could someone please direct me to a source that gives the rough diameters of the star classification types; O B A F G K M .

Something quick and dirty for rough 100D limmits would even do. Say along the lines of O= 0.5 AU, B= 2.8 AU, A= 4 AU
F= 7 AU or whatever... clearly I'm clueless as to this

I basically just want to work out which of a stars orbits would be within it's own 100D limmit.
TNE has each stars inner habitable and outer orbits etc but doesn't show where their 100d's are.
Thanks in advance to all those budding stellar cartographers who I hope will jump all over this

P.S. If it's not breaking anyone's copywrite posting a list right here would be the bees knees.

 

[RainOfSteel]

There have been some pretty heft discussion of this on the TML.

First, Book 6: Scouts, has a table of Stellar Radii and Mass.

Second, here's the Stuff Online discussion on Tidal Effects: Stuff Online: Tidal Effects


Heres one link to a TML discussion TML 100 Diameters From a Star


However, just to muddy the waters, I have my own cute question. Since a black hole has no diameter, how close can you jump to it? <no, I don't expect an answer here, I asked this on another TML thread or CotI topic way back, and got the answer I wanted>

 

[Straybow]

Oops, ya got it backwards. For Type V Main Sequence stars Ms are smallest and on up. Fs and As aren't too much bigger than than Sol (Vesta is an exception because it appears to be moving towards Type IV Subgiant). Bs and Os get big.

The real problem shows up with Type I-IV stars. Because they are anywhere from 0.5-10 au in radius the 100D limit is effectively outside the star system!

(Of course, the event horizon of a BH does have a diameter.)

 

[Andrew Boulton]

This is why most people have ignored the stellar 100d problem for the last 20 years - it's often very difficult to work out. First, the stellar data isn't always available, and second, unless you've rolled up the whole system you don't know the location of the mainworld. Yes, you can just assume it's in the habitable zone, but in many cases there's no reason for it to be.

 

[RainOfSteel]

Originally posted by Straybow:


<snip>

(Of course, the event horizon of a BH does have a diameter.)

<snip>

That was the simplest answer to go with for game purposes.

 

[Badbru]

Somehow I just knew there wouldn't be a simple answer!

Mostly I try to put the main world in the habitable zone though I seem to recall atleast one system I detailed not having a Habitable zone.

I guess when I want a "Deep in the well" situation I'll just have to make the mainworld be a moon of a Gas giant, possibly necessitating placing the Gas giant in the H zone.

Incidentally TNE doesn't give sizes for Gas Giants either. I've improvised diameters; roll a d3; small gas giant 30,000km on 1&2 45,000km on 3&4 and 60,000km on 5&6. Large 90,000km on 1&2 105,000km on 3&4 and 120,000km on 5&6. Does this sound near enough to most people?

 

[Straybow]

I like how you get 4s, 5s, and 6s from a d3
Jupiter is 140k km in diameter, so you need to go at least that big. Some debate on how much bigger a GS will get as mass increases, but another 20k would not be unreasonable.

For small GS, maybe (2d6+5)·4k
For large GS, maybe (2d6+7)·8k

 

[Andrew Boulton]

Scouts says:

"Large gas giants range in size from 60,000 kilometers in radius to perhaps
120,000 kilometers in radius. Small gas giants range from about 20,000 kilometers
in radius to just under 60,000 kilometers in radius."

 

[Badbru]

Cool. Then I'm not that far off with gas giants then.

Thanks guys.

d3 in that you get three results from a d6 like that. We allways called it a d3 roll

 

[robject]

First point: gas giants can get quite large... I think they can get larger than 160,000km, although I'm not sure! I know they can become very, very massive, and at some point they blur into brown dwarfs, etc etc.

Originally posted by Andrew Boulton:
This is why most people have ignored the stellar 100d problem for the last 20 years - it's often very difficult to work out. First, the stellar data isn't always available, and second, unless you've rolled up the whole system you don't know the location of the mainworld. Yes, you can just assume it's in the habitable zone, but in many cases there's no reason for it to be.

Second point: I'm trying to solve this very problem from a different angle -- given the mainworld stats, determine its classification and orbital position, then write a non-standard UWP for the system. My full story, more or less, is here:

http://www.travellerrpg.com/cgi-bin/Trav/CotI/Discuss/ultimatebb.cgi?ubb=get_topic;f=51;t=000039;p=1#000010

 

[Anthony]

Gas giants, beyond jovian mass, retain nearly constant diameter up into the brown dwarf stage and most of the way until they reach stellar ignition, just getting denser and denser. Jupiter is probably not quite the largest possible radius for a gas giant, but it's close.