Default Suns

[Dr Beeb]

I was trying to understand what determines the Oolite default Sun size and colours, is the following correct?
Sun radius is *2 the planet radius
Sun hue is random upon each visit to that system?
No connection between radius and hue?
Sun to planet distance is 20* planet radius?

For BBC retro Elite-B I looked into the system seeds and found w2's high byte to be the most interesting/unused  random number. Its lower 4 bits are used to set (most of) the planet radius in Classic. So I used the upper 4 bits to determine the Sun radius (actually in Elite-B the Suns are all the same size, the thing that is affected is how close you have to get to the star for fuel scooping to work. Fuel scooping at large stars is not possible due to the cabin temperature vs the whole disc of a red dwarf still being visible as the fuel scoop starts, which gives the illusion of star size).

The text description on Elite-B's charts uses the following scheme based on the highest nibble of w2:

• 0x0 Red Dwarf
  0x1 Orange Dwarf
  0x2 Orange Dwarf
  0x3 Orange Dwarf
  0x4 Orange Dwarf
  0x5 Yellow Dwarf
  0x6 Yellow Dwarf
  0x7 Yellow Dwarf
  0x8 Yellow Dwarf
  0x9 Yellow-white
  0xA Yellow-white
  0xB Blue-white
  0xC Blue-white
  0xD Red Giant
  0xE Red Giant
  0xF Blue Giant

The above could be further refined, I was limited by number of byte etc. available. I didn't have just 'white stars' as to say 'Star is White' in the text sounded a bit silly, and I didn't have space to say 'Main-sequence white' etc.

Note the above is not a complete list of star categories, nor probability distribution of occurrence, the distribution is my guess as to what is most likely to be habitable by Elite's species.

And of course I had to satisfy canon. I found Lave orbiting an Orange Dwarf which reduced how many Red Dwarfs are present in GalCop in the above scheme as Lave had a value of 0x1. Whether Red Dwarfs are inhabitable is a topic of debate anyway regarding X-ray flares and tidal locking. Going through Rob Holdstock's The Dark Wheel, it mentions Xezaor is close to a dying, dim red star. I guess it is in a Red Giant phase which can last a billion years so I figured ok to use that for 0xE. This scheme also left Tionisla as a Red Giant, at 0xD, which may conflict with other canon but sounds appropriate for the Graveyard.

Some stars of interest ended up as follows:

• Diso Yellow Dwarf 0x8
  Lave Orange Dwarf 0x1
  Leesti Orange Dwarf 0x4
  Reidquat Blue-white 0xB
  Tionisla Red Giant 0xD
  Zaonce Yellow-white 0xA

I also used this scheme to set the Sun-planet distance based on how big/hot the star was (some 6502 code for those who miss that sort of thing):

Code: Select all

LDA W2H: LSR A: LSR A: LSR A: LSR A
LSR A: LSR A: ADC #5: STA stop

which gives a value between 5 and 9 for the distance stop, but Oolite probably needs different scaling.

[cim]

Sun radius is *2 the planet radius

Between 1.5 and 3.5 planet radius, biased towards the middle.

Sun hue is random upon each visit to that system?

It's static.

No connection between radius and hue?

No.

Sun to planet distance is 20* planet radius?

16 to 24 times, biased towards the middle.