[CWBP2] Astrophysics

[Azélor]

I'm not opposed to the idea of having a gas giant in the inner system and the impact would be small. Unless the planets are close to each other and/or their obit have the same angle of inclination, the Gas giant will have no negative impact.

[Falconius]

K, here's what I have so far then (Azelors orginals will be tagged [A]):
Our star
Planet 1: [A] Tide locked, close to sun
Planet 2: [A] Old drifter, much orbital debris
Planet 3: Inner gas giant
Planet 4: [A] Earth-like but 30% bigger, orbit close to CWBP 2, two moons
Planet 5: CWBP 2 planet
Planet 6: [A] Ice rock smaller than Venus
Planet 7: [A] Blue gas giant
Planet 8: Somthing to just finish up the system, I think one more would be nice

and the Second star with associated nebula and possible planets to be filled in at a future date.

[Ghostman]

Add one more gas giant, at a far away orbit but close enough so that all 8 other planets will be visible from the homeworld. That way there'll be 9 "wandering stars" known to the people (the secondary sun counts as the 9th), which gives them a nice number to feature in astrology.

[Azélor]

Add one more gas giant, at a far away orbit but close enough so that all 8 other planets will be visible from the homeworld. That way there'll be 9 "wandering stars" known to the people (the secondary sun counts as the 9th), which gives them a nice number to feature in astrology.

and I assume that would be our 8th planet.

The second star is so dim that one or two planets would be brighter but only at their brightest. You see, their brightness will fluctuate a lot depending on their position. On the other hand, the second star will have a variation of only 7% luminosity due to the movement of the planet around the main star. This is considering that the second star is still at 75 AU from the main star. 75 AU (or 11 175 billion km) is what I considered a safe distance that allowed both stars to have their own system. Of course the orbit could be elliptical but I assume that if it's the case, 75 AU is the average distance. That would also influence the brightness perceived from the planet... but these are just details

Planets from the second star (if any) would be impossible to spot in the sky with the available technology. But they are free for speculators.

[Ghostman]

and I assume that would be our 8th planet.

No, I meant add a 9th planet in addition to whatever will be placed on the 8th spot. So there'd be a total of 9 planets (8 from the POV of the people living on the homeworld planet), which would probably be regarded as moving stars. As would the secondary sun.

[Falconius]

Planet 1: [A] Tide locked, close to sun
Planet 2: [A] Old drifter, much orbital debris
Planet 3: Inner gas giant
Planet 4: [A] Earth-like but 30% bigger, orbit close to CWBP 2, two moons
Planet 5: CWBP 2 planet
Planet 6: [A] Ice rock smaller than Venus
Planet 7: [A] Blue gas giant
Planet 8: Maybe a large terrestrial planet, probably some sort of ice planet?
Planet 9: Gas giant

The Second Star

[Jalyha]

Hi guys I like where this is going. I probably won't be able to wiggle participation in this project back into my new therapy schedule though so I won't start joining in the planning again until/unless I know for sure.


xoxoxo

[EpicSpire]

I'd like to suggest using a program/game called Universe Sandbox (I bought it on Steam for $9.99). they are coming out with a new one soon, but i have the original (not sure if you guys/gals have been using this, i only read the first few posts and skimmed them at that). I bought it to run simulations for the world i am creating. Similar to what i have read here, i wanted my planet to orbit a White Dwarf star, so i wanted to get the yearly orbit and temperature of the planet the way i wanted. the following is the information i used when creating my system.

Star:

Mass: 4.29 Suns
Diameter: 465188 km (bigger than i originally wanted, but seems to work in the model i made)
Density: 162 grams per cubic centimeter (g/cm^3)

Temperature: 12050 Kelvin (Our sun is 5000ish Kelvin)
Luminosity: 2.12 L (earth's sun = 1 L, this brightness can be dimmed by atmospheric conditions)

it is blueish white

Planet:

Mass: 1 earth
Diam: 23853 km (Almost twice the size of Earth, but that's because my world lacks sufficient metals and it has to be bigger to equal the mass needed to have Earth like weight)
Density: .84 g/cm^3

Average Temp: 17.6 C or about 63 F. (close to Earth)
Orbital period 300 days (the gravity of the sun causes the years to be shorter, since the planet is orbiting it faster, at 365 days the temp would be too cold)

Moon:

Mass: 1 Lunar mass
Diam: 4586 km
Density: 1.46 g/cm^3
Avg Temp: 17.4 C or About 63 F (my moon has an atmosphere and would be able to support life if the inhabitants of the planet had the technology and means to reach it)
Orbital period: 30 days

[su_liam]

The mass-luminosity relationship on your star is badly cockeyed. A star with a mass of 4.29 Sols should have a luminosity of much more than 4.29. As a rule of thumb, I use L = M^3.5.

For planets with the same insolation, larger stars should have longer years. I'm not even sure if a mass of 4.29 Sols would have a sufficiently long life to evolve complex.. life.

EDIT:
For reference, looking at the table at the end of Gillett's World-Building a A0 main-sequence star with a mass of 3.0 Sols has a luminosity of 64 Sols and a B5 main-sequence star with a mass of 5.8 Sols has 810 times the luminosity of the Sun. That brackets the 4.29 Solar masses given for the CWBP2 planet's star. The temperature seems plausible for a star of that mass, but the MS lifetime of such a star would be somewhere between 72 and 470 million years. Life would have to be introduced from elsewhere.

[Azélor]

Thanks, I already know about that software but not that a second version is coming.

You planet is not in the habitable zone, it will be cooked like a roasted chicken in no time.