- #1
jscroft
- 13
- 0
Must a "Hot Jupiter" be relatively young?
A large proportion of exoplanets so far discovered are "hot Jupiters," large gas giants orbiting very close (< 0.1 AU) to their primaries.
It seems to me that a gas giant orbiting at such a close distance ought to experience significant friction as it passes through its primary's coronal envelope. I also imagine that any orbital eccentricity on the part of the planet or wobble on the part of the primary would generate significant tidal pumping within the body of the planet, damping these motions by converting their energy to heat, which would cause the planet's gas envelope to expand and add to its drag coefficient.
Finally, I suppose that the plasma composition of the coronal medium—being electrically active—would also facilitate energy transport, although I'm not sure in which direction.
The upshot is that I wonder whether such a planet could orbit its primary for very long before orbital decay removed it from observation? And, if not, what might that say about (a) the mechanism of hot Jupiter genesis—formation? ejection? capture?—and (b) the likelihood of same.
A large proportion of exoplanets so far discovered are "hot Jupiters," large gas giants orbiting very close (< 0.1 AU) to their primaries.
It seems to me that a gas giant orbiting at such a close distance ought to experience significant friction as it passes through its primary's coronal envelope. I also imagine that any orbital eccentricity on the part of the planet or wobble on the part of the primary would generate significant tidal pumping within the body of the planet, damping these motions by converting their energy to heat, which would cause the planet's gas envelope to expand and add to its drag coefficient.
Finally, I suppose that the plasma composition of the coronal medium—being electrically active—would also facilitate energy transport, although I'm not sure in which direction.
The upshot is that I wonder whether such a planet could orbit its primary for very long before orbital decay removed it from observation? And, if not, what might that say about (a) the mechanism of hot Jupiter genesis—formation? ejection? capture?—and (b) the likelihood of same.