1. Warm Saturns: Rings Around Exoplanets that Reside Inside the Ice Line Extreme Solar Systems II September. 14 th 2011 Schlichting & Chang (2011), ApJ 734, 117 Hilke E. Schlichting (UCLA) Hubble Postdoctoral Fellow

2. Obvious Obstacles: Best ring candidates have a > 0.1 AU Ring lifetimes due to Poynting-Robertson drag 10 6 -10 9 years Rings must be rocky!Poynting-Robertson drag timescale

3. Rings vs. Moons R Roche RPRP ρ ice ~ 1g/cm 3 ρ rock ~ 2-5g/cm 3

4. Roche Radius For Saturn: R Roche /R P ~2.2 (ice:1g/cm 3 ) R Roche /R P ~1.5 (rock:3g/cm 3 ) (Schlichting & Chang, 2011) ρ =3g/cm 3 ρ =5g/cm 3

5. Laplace Plane R L > R Roche R L < R Roche J 2 : Quadrupole Gravitational Harmonic

6. Warped Rings (Schlichting & Chang, 2011) For Reference: J 2 of Uranus & Neptune ~ 0.003 J 2 of Jupiter & Saturn ~ 0.01

7. Ring Light Curves Quadratic Limb Darkening as in Mandel & Agol (2001), for Ring light curves see also Barnes & Fortney (2004) R P =1 R J R R1 =2.0 R P R P2 =2.5 R P R P =1 R J R R1 =1.5 R P R P2 =2.5 R P R P =1 R J R R1 =2.0 R P R P2 =2.5 R P R P =1.8 R J Transit duration ~ 6 hours Time in ingress/egress ~ 2 hours

8. Ring Properties & Possibility for Detection Rings may be common Rings must consist of rocky material Some Rings maybe warped J 2 Best candidates for ring detection have a > 0.1 AU Obliquity damping, temperature, ideally want short cadence