Planets In Orbit Around Two Stars: Not All Orbits Are Created Equal

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Welcome, my name is Phil, and in this video I explain the different types of orbit planets can have when part of a binary star system.
Many exoplanets have now been discovered around two stars. The orbit that a planet can have are not equally stable and can impact the long term fate of the planet.
Two orbital configurations exist for these planets.
P - Type: Planets orbit around the outside of both stars.
S - Type: Planets orbit one of the stars which orbits the common centre of mass for both stars.
Planets that orbit around the outside of both stars (P Type) can remain stable for long periods of time. However, stars that orbit just one of the stars in the system are exposed to additional gravitational perturbations from the 2nd star, which can can quickly destabilize the planet.

[@spaced___x]

Could you perhaps make a video about how binary star systems (or star systems with multiple stars for that matter) even from?

[@AstroPhil2000]

Yes I can definitely do this. Most stars form in groups as the cloud locally collapses. Probably be a few months but I will get round to doing a video on the formation of multiple star systems.

[@AstroPhil2000]

Just got round to making the video on how binary stars might form. One of the ways they can form is from disc fragmentation. This is where a disc around a young star gravitationally collapses and starts to form a 2nd star -ruclips.net/video/ZauSec6tDGk/видео.html

[@spaced___x]

@@AstroPhil2000 Yes, I already watched it when it came out yesterday, and it's really amazing!

[@AstroPhil2000]

Thanks, glad you enjoyed!

[@user-rc7cf1um8t]

Nicz

[@Ashaira]

Nice explanation. I'm curios. Is it possible to have an S type orbit that is so on the edge between the two stars that when it passes between them it might switch to orbiting the other star?

[@AstroPhil2000]

Thanks, yes it is possible for planets (and stars in multiple systems) to switch places and orbits. These would be unstable and does highlight how planets that do this would end up in these systems. For example, it is hard for planets to form around multiple stars, which might suggest they were captured after the stars formed. These planets have been nicknamed "star hoppers" and if you are interested there are scientific papers discussing it in detail:
Kratter, K.M. and Perets, H.B., 2012. Star hoppers: planet instability and capture in evolving binary systems. The Astrophysical Journal, 753(1), p.91.