It is back to the non-research grind now, but that didn't stop me from stealing a couple hours to work on Foreman-Mackey and my "stellar clocks" project. My question was: How precisely can you phase up or measure the time using a transiting hot Jupiter. That is, how good is a hot Jupiter as a clock? If good, we could use it for all kinds of fun things.
I started with fake data. As my loyal reader knows, I am against using fake data; all it provides is a functional test of your code! But over the years I have come around: After all, it provides a functional test of your code! It also permits you to check your results with absolutely known input assumptions; that is, it provides sanity checking on your estimates of (in this case) the precision you expect.
I find, with extremely optimistic assumptions (about the period, depth, duration, ingress time, gravitational dynamics, and, of course, photon noise), that a high-quality transiting hot Jupiter in Kepler normal-cadence data could, over the lifetime of the now-over Kepler mission, provide a time standard that is good to a few tenths of a second. This agrees with the order-of-magnitude calculation I had made myself earlier and suggests that we might be able to do some timing experiments.