The artist's conception, with Jupiter-like bands running at an angle through the principle tidal axis really bugs me. If there's some bizarre mechanism that makes this even remotely plausible, it ought to have been explained. If (as I think is more likely) it's just a case of someone who didn't understand the article commissioning and approving and illustration by someone else who didn't understand it... why? Why even bother? It would be clearer with no illustration than with a misleading picture.
(The worst example of this I've seen was a few years back, when CNN briefly used a picture of a cow to "illustrate" an article about coconut milk).
What angle? The cloud bands are running at right angles to the terminator and roughly parallel to the axis of tidal stretching. Are you looking at "Image B"? That one might look a like tricky, but it's just because you're looking a bit upwards at one of the poles, so you can see the curvature of the cloud bands around the planet.
Now, would clouds around such a weird planet take such a familiar shape? I doubt it. But going with that familiar shape is probably better then making up something weird to happen at the stretched ends.
Right, that's what I'm objecting to. With tidal forces that strong, there should be no rotation parallel to the axis of tidal stretching. In the two-body reference frame the axis of rotation should be identical to the axis of rotation (tidal locking). So it should keep one pole towards the star.
The terminator is only secondarily significant here, but since it lies in a plane perpendicular to this axis, any bands should be parallel to it. But since this means that there will be a "hot side" and a "cold side" and convective cells between these will probably eliminate any banding.
Well, if it's tidally locked (which it probably is and the paper doesn't disabuse me), then both its rotation and orbit are about 8 hours on the sameish axis. So it's still spinning pretty dang fast, enough that the gas doesn't have to settle into hot and cold sides. I can't fully parse the part of the paper where they talk about the wind structure, but they do seem to think it still has some banding. Section 5: https://iopscience.iop.org/article/10.3847/2041-8213/ae157c (linked elsewhere, here again for convenience).
> both its rotation and orbit are about 8 hours on the sameish axis. So
> it's still spinning pretty dang fast, enough that the gas doesn't have
> to settle into hot and cold sides.
Except that by spinning on the same axis [more correctly, on axes normal to the same plane] at the same rate the atmosphere is stationary in the co-rotating frame. That's what it means to be tidally locked. The gas is already divided into a hot side (always facing the star) and a cold side (always facing away).
(The worst example of this I've seen was a few years back, when CNN briefly used a picture of a cow to "illustrate" an article about coconut milk).