Assistant Research Scientist, University of California, San Diego
Exploring exoplanets with direct imaging and novel high-resolution spectroscopy techniques.
Searching for exomoons
The development of novel instruments combining the power of high-resolution spectroscopy and high-contrast imaging is enabling the first direct radial velocity measurements of planets. This will allow us to detect wobble of these planets caused by orbiting satellites.
The figure below shows the future prospects for exomoon detections around the brown dwarf companion HR 7672 B. From ~1.5 nights of observations with the KPIC instrument, I have demonstrated a sensitivity to satellites with a mass ratio of 1-4% at separations similar to the Galilean moons (Dashed blue). The figure also includes simulated sensitivity for future instruments like Keck/KPIC II, Keck/HISPEC, and TMT/MODHIS (colored curves) assuming 6 nights of observations over a 25-day period.
The mass ratios of the Galilean satellites are shown as black dots for comparison. Their predicted scaled-up mass ratios, q, accounting for the larger mass, M, of the brown dwarf compared to Jupiter are shown as grey crosses. The Roche limit is computed for both a rigid and a fluid satellite shown as the inner and outer greyed region respectively. The black dashed lines represent the astrometric sensitivity of VLTI/Gravity and the vertical gray scale bars represent direct imaging of satellites.
Ruffio J.-B. et al. (submitted)
Measuring the composition of exoplanets
The formation of directly imaged planets, whether from accretion of planetesimals or from the collapse of the circumstellar disk, remains poorly understood. Different formation models predict different atmospheric compositions, so spectroscopic characterization of exoplanets might be used to inform their formation pathway.
Looking for new planets
Get in touch at jruffio at caltech.edu