By exploring exoplanet atmospheres across multiple spectral resolutions we achieved multiple successes:
- first detection of molecular features using high resolution cross-correlation spectroscopy (HRCCS) in the M-band (4-5 micron);
- first detection of SiO in an sub-stellar atmosphere with HRCCS;
- first detection of CO lines in emission in a hot Jupiter;
- first demonstration that 3D atmospheric dynamics, such as offset hotspots, can be revealed in high resolution spectroscopic phase curves through Bayesian retrievals;
- measured chemical and cloud constraints for a sub-Neptune atmosphere with HRCCS as well as achieved with space-based telescopes (JWST).
Our success with the M-band means that METIS/ELT (3-5 microns) is a viable and powerful machine for biosignature hunting. We further contributed to the first discovery of hydroxyl radical (OH) emission and the use of its individual spectroscopic bands as an exoplanet thermometer. We also demonstrated the importance of including disequilibrium modelling in HRCCS.
We made major breakthroughs in the development of HRCCS for reflected light studies with the ELT, using the world’s largest optical telescope, the combined 16-m VLT, to observe the reflective atmosphere of a hot Neptune. The data were so sensitive that they ruled out the presence of titanium oxide. This sensitivity is extremely promising for using the technique to study biosignatures with the ELT. We simulated the capability of HARMONI/ELT to do this for the nearest rocky exoplanet, Proxima b, resulting in urgent interventions on the design of its coronagraph to enable it. We further made recommendations for future space-based reflected light instruments, responding to calls from ESA’s Voyage 2050, and setting coronagraphic requirements for the Habitable Worlds Observatory.
Using state-of-the-art optics and advanced data processing, we monitored light directly from a planetary mass companion to a repeatable 4% precision level using ground-based telescopes, the most precise to date. Our studies are not yet limited by a noise floor, indicating that sub-1% precision may be possible, which would allow mapping of exoplanet weather systems and the search for their transiting exomoons. This innovative and novel technology combination will become a primary exoplanet characterisation tool for the ELT's METIS, ANDES, and PCS.
We have disseminated our results via numerous talks at international academic conferences, including 11 keynote talks; as well as through public engagement, reaching ~2 million listeners on BBC Radio 4’s In Our Time (
https://www.bbc.co.uk/programmes/m0025vvd(odnośnik otworzy się w nowym oknie)).
