Traveller MTU World of Corsairs

And just like that, I can no longer get Heaven & Earth to run - a component, TwistedPixel, apparently got nerfed in one of the OS updates. And the site that has it is actually still around but 25 years old and only lets you download from a Lycos server or something. So, I am really going to have to get my version working as not sure I want to roll up all this stuff all the time.

But a quick description, then the details:

Corsairs 1316 X762570-4 F0 V M5 D   

An average sized world orbiting an F0 V star that has a close binary dwarf M0 companion. There are two planets in the system, Corsairs is in the 5th orbit and takes 3.7 years to orbit. A large, captured planet has an elliptical orbit that goes inside the main world's orbit every 8 years. The dwarf star orbits close to the main star, a bright white star. It is rarely visible but is known as the Candle when it is seen. Low tech, it's one amazing aspect is a mineral called repellium that defies gravity. 

Despite being a TL-4 world, there are large 2000-meter cylinders, known as Spires, that use grav engines, made from bonded superdense and float a couple thousand meters above the surface. At one point this was either a colony of some stellar government or independently developed similar technologies. It is currently a balkanized planet with several various governments vying for control over resources. 

The fauna on this planet is extremely dangerous: mega-fauna prowl the surface and fly high in the atmosphere. It is only the middle latitudes, where floating islands and the Spires exist, that is reasonably safe from predators. 

The Scouts finally pegged hydrographics at 20%. There is a molten sea of an unknown substance that covers over 40% of the surface, but there are large lakes on the floating islands. The relatively small population has no issues with water. One theory is that the interactions of the binary stars cause the interior mantle to be closer to the surface. More research is recommended.

There are also 2 humanoid species - a bat-type humanoid that seem to be native. and what almost appears to be Aslan but smaller, and more humanoid. Reseach is recommended.

The Molten Seas

Generating the Details

In looking at my little quadrant, there are a number of x-planets out there. I've already set up the stats for the world but let me manually go through the system to generate the rest of the Corsairs system. 

Rolling for the nature, I get 11, so it is a binary star system. And I'll have to think about how that works out - will probably stick the companion star, regardless of my roll, in a far orbit so that it is just a really bright star. As it has never come up in the games I've run. Yet. We get 7 + 4, 11, which is a type F star, 8 + 4 = 12, or size D, or dwarf. That is going to be interesting, especially as there is not a table for that - the tables go from Ia to V. (Edit - that table for dwarfs is there but on the previous page due to space). So we'll just fudge that to get a V star, a main sequence star. There does not seem to be any rules for the numeric value (F0, F5, etc). Rolling a die, 2, and will go with a F0 type V star. The habitable zone, where our Corsairs world lives, is in the 5th orbit. From Wikipedia:

An F-type main-sequence star[a] is a main-sequence, core-hydrogen-fusing star of spectral type F. Such stars will generally have a luminosity class of V. They have from around 1.1 to 1.6 times the mass of the Sun and surface temperatures between about 6,000 and 7,200 K. This temperature range gives the F-type stars a whitish hue when observed through the atmosphere. Notable examples include Procyon A, Gamma Virginis A and B, and Tabby's Star.

As we have a companion star and size. If I am reading this right, we actually use the original rolls for the primary as DMs. For type, 5 + 7 makes the companion star a type M, and size 9 + 8, D for dwarf (as it exceeds the table. I do have that in the rolls to determine min and max rolls). The M0 dwarf star is in orbit 2. Really - the star is closely orbiting the main star and inside the orbit of the main world? Well, a type M star is pretty small and not too hot. It would make for interesting shadows, I think. And hey - perhaps having that 2nd star so close is one of the reasons we have the Molten Seas. 

Next step, E, is getting the number of orbits. And there are a lot of potential DMs, though none for a F0 V star. Rolling a 3 means there are only 2 orbits. Which is orbit 2 for the dwarf star, and orbit 5 for the main world. Perhaps why this was never visited much - no gas giants, only 1 actual planet. But that does make the PGB 900. Which in the SEC file looks like this now in my revised file (do not copy/paste as I did remove a few spaces to make it fit here:

Corsairs      1316 X762570-4            900 Na F0 V M5 D   

But those 2 orbits mean I do not even need to roll for gas giants or belts. I do need to track that in the system generation. 

Step G mentions captured planets and empty orbits. We already know only orbits 2 (.7AU) an d5 (2.8AU) are filled and all others are empty. Rolling a 6 on the captured planets table, there is (a 2) 1 captured planet. It is usually around orbit 6 (outside Corsairs) but has a 10% deviation from that. Which is not too much. 

We have some additional rolls now - moons. 1d-3 and Corsairs sadly has no moon.

And that pretty much finishes that up - the captured planets I had entirely forgotten about. If I even know it was there - I did not roll up too many systems. And no moons or belts or gas giants. That will make drawing out the system fairly simple. Though it won't be via the IIS - maybe the League of Planets has a Scout service as well. Will have to recheck my ancient notes. 

Captured planet - X-BF8000-0 (a type F atmosphere is thin, low. and that 80% hydrographics is really when the orbit swings in a bit, else it is always ice I think). The captured planet has some potential - is it an interstellar planet captured, did Grandfather stick it there, is there anything there?

Where it is on my maps now. Off the beaten path!

thank you poster maker!

Layers

Pretty sure I previously posted this, but just in case:

Here there be monsters! If you go too high or go too low

An AI overview

When I asked Copilot about it, it also remembered I've asked questions about Brass Rings (used it to generate names and a few things. Which only a couple got used but it is interesting that each session is not its own thing, but it now remembers previous discussions. Some very interesting privacy issues here!

A fascinating pairing! An M0 dwarf star orbiting an F0 V star would be a striking contrast in both brightness and color. I found some images that illustrate this kind of stellar relationship—those are now visible in the card above. ✅

Here’s how the scene would play out visually and physically:

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🌟 Visual Description

• F0 V Star

  • Color: Brilliant white with a slight bluish tint
  • Temperature: ~7,200 K
  • Size: About 1.6 times the Sun’s mass and nearly twice its radius
  • Luminosity: ~7 times that of the Sun
  • Appearance: Dominant in the sky, radiating intense light and UV

• M0 Dwarf Star

  • Color: Deep orange to red
  • Temperature: ~3,800 K
  • Size: Roughly half the Sun’s radius and mass
  • Luminosity: Just ~0.08 times the Sun’s
  • Appearance: A faint ember next to the blazing F0 star, barely visible in the glare unless viewed in infrared

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🔭 Orbital Dynamics & Contrast

• The M0 dwarf would likely orbit at a considerable distance to remain gravitationally stable, unless it's a tight binary system.
• In a wide binary, the F0 star would dominate the visual field, with the M0 dwarf appearing as a dim companion.
• In a close binary, the contrast would be dramatic—like a candle next to a floodlight. The M0 dwarf might even be lost in the F0 star’s glare in visible light.

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🧠 Fun Thought for World-Building

If you’re imagining this system for your Brass Rings universe, consider:

• The M0 dwarf as a hidden refuge or a stealthy observatory tucked in the shadow of its dazzling sibling.
• The F0 star’s intense UV radiation could create dramatic auroras or force civilizations to live underground or underwater.

Let me know if you want to simulate orbital paths, habitable zones, or even design a planet that dances between these two stars.

And then I asked how long it would take to orbit:

A planet orbiting 2.8 AU from an F0 V star would take about 3.7 Earth years to complete one orbit. That’s a bit longer than Mars’s orbit around the Sun, but with a much hotter and more luminous central star.

If you’re imagining a world in this orbit, it could have dramatic seasonal shifts depending on axial tilt, and the stellar radiation would be more intense than Earth receives—even at that distance.

Software updates   

Apparently, I am taking a break - it got to be a bit too much like work. I will get back to it, but I also need to get next Monday's game figured out before Monday, and work on the actual Corsairs game and not the Traveller interpretation of it. It helped, though, that I ran through the system generation manually for the first time in a long, long time! Old school and analog.