A Strained Astrophysical Model
Astrophysicists recently discovered a very unusual planetary system. It consists of a double star with a large circumstellar disk. The truly odd thing is that it also has an 11-Jupiter-mass planet that is orbiting the stellar system in a highly unusual way. Its orbit is VERY far from the double star center; it is also very eccentric; and it is “highly misaligned” with the plane of the stellar system.
https://phys.org/news/2020-12-hubble-pins-weird-exoplanet-far-flung.html
The burning question for astrophysicists is how could such a system form. Here is their model. “The prevailing theory is that it formed much closer to its stars, about three times the distance that Earth is from the Sun. But drag within the system’s gas disk caused the planet’s orbit to decay, forcing it to migrate inward toward its stellar pair. The gravitational effects from the whirling twin stars then kicked it out onto an eccentric orbit that almost threw it out of the system and into the void of interstellar space. Then a passing star from outside the system stabilized the exoplanet’s orbit and prevented it from leaving its home system.”
This model seems to involve multiple “then a miracle happens” steps, especially the last one where the “passing star” just happens to nudge the planet into a stable orbit.
As yet there is no mention of the possibility of a capture model for this unusual planet, but that seems less strained to me. We have discovered that there are large numbers of rogue planets roaming free in our galaxy (courtesy of Sumi et al, 2011). The estimated typical mass of the rogue planets is virtually the same as the planet in question. The orbit of that planet has the odd characteristics expected for capture of a rogue planet.
There is no guarantee that the capture model is correct, but it should be considered a viable model, and perhaps the least far-fetched? Why are astrophysicists so adamant in ignoring capture models for stellar systems. Capture models certainly apply on atomic and galactic scales. Why ignore them on stellar scales?