How have we modified the nebular theory to take the oddities of extrasolar planets into account?
We haven’t. The only modification to the nebular theory is that instead of it being applied just to our own solar system, the theory is now being applied universe wide. The production method is the same. The orbits of extrasolar planets can be somewhat eccentric due to something known as planet-planet scattering. Which, as you may already know, is when planets get too close together (because of their orbit, possibly caused by a disturbance in that system) and the gravitational pull will result in their irregular orbits or a “sling shot” effect. So you’ll end up with oval/elliptical/irregular orbits instead of the circular orbits we have in our own solar system. The only real difference (dectection-wise) is that extrasolar planets are detected through methods such as radial velocity observations, pulsar timing etc as opposed to direct imaging because the light from the parent star usually glares out the planet, making it hard to detect through conventional methods. The properties of ext
