Then now select a time space that you increase the diameter of your protoplanets ( yes no choice since we cant put billions of object in orbit, we need to help it).select a time space between 20 to 100 yrs (depend how fast the simulation disk goes and how big is your accretion disk.if its small it will eliminate the objects faster by colision.if its bigger well it will mostly catapult objects. PS i normally put moon mass objects in the accretion disk (at the start).because i don t want to end up with only brown dwarfs when i put back to scale the new born solar system. the mass will increase so lock the diameter for this step. My star is a 0,75 solar Mass (0,75 jupiter Mass in the accretion disk simulation) i add 1,8 grm/cm3 = 10.84 gr/cm3. Ex: 2250 km diameter with a density of 9.54. Running the accretion Disk and making the protoplanets grow.Īt the start of the accretion disk.if i have an object over 2000 km in diameter, i normally increase its density.those will be my dominants planets (like jupiter in our own solar system) But this depend on the mass of the star. I normally click many times on the 3 just to be sure, because when you have many objects your simulation is much slower. When you save delet trails, impact marks and will reduce the size of your simulation.if you don t do won t save. Wait at least a universe sandbox year to put back dust and impact marks. PS don t forget to desactivate dust, trail and impacts marks at the start.if not your universe sandbox will crash.then bye bye to your work. And i continu like this until i m satisfied. I normally put 2 objects of about the same mass on the same orbit but 180 degrees from each others.so one is on the right side of the ''protostar'' and the other one is on the other left side.

Dont put dense objects on it.more they are dense.smaller they are.so they ll be fewer colisions. Then for the disk (depend on your computer speed and power), put many objects in orbit, make them explode in 500 objects (select the average speed and the mass of the object). Ex a 0.15 Sun Mass Star will be 0.15 Jupiter Mass Object. But reduce its size into a Jupiter mass object.

First you need to put a center object mass like a M dwarf star, a brown dwarf and etc.

Make a pulsar in universe sandbox 2