resolution to date when considering both their angular separations and
ux ratios. We developed a forward modeling framework that allows us to jointly t the spectra of the planets and the diracted starlight simultaneously in a likelihood-based approach and obtained posterior probabilities on their
eective temperatures, surface gravities, radial velocities, and spins. We measured v sin(i) values of 10.1+2.8-2.7 km/s for HR 8799 d and 15.0+2.3-2:6 km/s for HR 8799 e, and placed an upper limit of < 14 km/s of HR 8799 c. Under two dierent assumptions of their obliquities, we found tentative evidence that
rotation velocity is anti-correlated with companion mass, which could indicate that magnetic braking with a circumplanetary disk at early times is less ecient at spinning down lower mass planets.
|Publication status||Accepted/In press - 9 Jul 2021|