Give the oversized planet a ring

1 · Too wide for its weight

Beginner

The companion weighs about 9.4 Jupiters and measures 1.7 Jupiter radii. Why is that radius a problem?

Being heavier, it should be much wider still Cool and old, it should be about Jupiter's size Far from its star, it should be far more puffed up

2 · Tilt the ring

A ring is unlikely to be seen exactly face-on. Tilt it like Saturn's: Saturn's axis leans 26.7°, so for an orbit seen edge-on, as here, its ring sits 63.3° from face-on.

Intermediate

You find about 2.4 Rₚ. The Roche limit is about 2.46 Rₚ times the cube root of the density ratio, planet over grains. With a planet near 9 g/cm³ and grains near 1 g/cm³, where does it lie?

Near 22 Rₚ Near 2.5 Rₚ Near 5 Rₚ

3 · How far can it tilt?

Expert

The best fits tilt the ring 78 to 84° from face-on. Seen exactly edge-on, what ring would block enough light?

No ring at all, whatever its size A ring of 1.6 Rₚ, as seen face-on A ring of about 5 Rₚ, at the limit

4 · Tell the two pictures apart

Expert

The ringed planet and the bare sphere block the same light at mid-transit. Where can a new observation tell them apart?

In the depth of the dip, at mid-transit In the entry and exit of the transit In the rise, 0.25 days after mid-transit

Ring in place

—