Characterizing exoplanetary systems with JWST direct imaging and beyond 

Supervisor: Professor Sasha Hinkley

Although the majority of exoplanets identified to date have only been indirectly detected based on some effect they have on their host star’s light, we now have an increasingly large number of direct detections of extrasolar giant planets at wide orbital separations. In this PhD project, the student will undertake an observational effort potentially involving several international teams to detect and characterize extrasolar planets using coronagraphy and spectroscopy on with James Webb Space Telescope (JWST) as well as transformative ground-based instruments such as GRAVITY or SPHERE at the Very Large Telescope.  

The newly commissioned JWST is already demonstrating that it is opening completely new areas of exoplanet characterization, by directly imaging exoplanets at totally new wavelengths, giving us insight into their atmospheric compositions and dynamics. JWST also has sensitivity that is vastly superior to ground-based observatories, allowing us to search for a totally new class of planets: analogues of our own Jupiter and Saturn at wide orbital separations. 

The James Webb Space Telescope (left) launched in late 2021 is transforming our understanding of exoplanet atmospheres and architectures. This PhD project will focus partly on using JWST coronagraphic images of nearby stars (centre), that may host planetary mass companions (right)

The new PhD student will use upcoming and archival coronagraphic (and possibly spectroscopic) datasets from a suite of different JWST instruments. These datasets originate from the 70-hour Early Release Science (ERS) Program and a 25-hour coronagraphic program to be carried out in Cycle 1 searching for planetary sculptors in systems with well-defined debris structures identified by ALMA, both led by Professor Hinkley. This PhD project will be primarily focussed on data processing, using advanced image processing techniques. The results of these studies will help to illuminate our understanding of the outer architectures of planetary systems, as well as possibly reveal new aspects of their atmospheres, forming a synergy with the world-leading exoplanet atmosphere modelling group at Exeter. The exact focus of this PhD project is flexible, depending on the interest of the student and the outcome of future observing proposals.  

The PhD student will immediately join international teams in which the supervisor is closely involved, including a large JWST ERS team of ~100 researchers across the globe focussing on exoplanet imaging and spectroscopy with JWST for which Prof. Hinkley is the Principal Investigator. There is also the strong possibility of working with the large international team committed to using the GRAVITY instrument at VLT to measure precise orbits and spectroscopy of extrasolar planets to answer fundamental questions about the composition and architectures of extrasolar systems. Such a PhD position will position the student extremely well for future studies of exoplanets with JWST, VLT, as well as the Extremely Large Telescope, with an expected first light in 2028. 

Background information can be found in Hinkley et al. (2022) and Carter et al (2022). 

For more information contact Professor Sasha Hinkley