Hi, we're trying to investigate if we can put upper limits on the mass of HR8799's debris disc, by seeing how massive it can be before it destabilises the tightly packed planets.
We were thinking about using MEGNO to quantify the stability, but have a problem; our MEGNO values become very high, even if the planets are stable, because we think the MEGNO is also factoring in the disc particles, which can be destabilised by e.g. MMRs. We don't care about the stability of individual disc particles, just the planets; is there a way to get Rebound to calculate MEGNO (or any other stability indicator) for just the planets (i.e. a subset of bodies in the system)?
We tried initialising MEGNO after adding the planets but before the disc, but this didn't produce the expected results (even in a simulation where the system explodes, MEGNO still came out as 2). As we understand it, Rebound implements MEGNO by creating one ghost particle for each body in the system.
Any advice would be much appreciated!
Hi, we're trying to investigate if we can put upper limits on the mass of HR8799's debris disc, by seeing how massive it can be before it destabilises the tightly packed planets.
We were thinking about using MEGNO to quantify the stability, but have a problem; our MEGNO values become very high, even if the planets are stable, because we think the MEGNO is also factoring in the disc particles, which can be destabilised by e.g. MMRs. We don't care about the stability of individual disc particles, just the planets; is there a way to get Rebound to calculate MEGNO (or any other stability indicator) for just the planets (i.e. a subset of bodies in the system)?
We tried initialising MEGNO after adding the planets but before the disc, but this didn't produce the expected results (even in a simulation where the system explodes, MEGNO still came out as 2). As we understand it, Rebound implements MEGNO by creating one ghost particle for each body in the system.
Any advice would be much appreciated!