Two HoRSEs: High-Resolution Exoplanet and Stellar Characterization Today and in the ELT Era

In 2018 the first HoRSE ("High Resolution Spectroscopy of Exoplanets") conference was conceived to bring together the stellar and exoplanet community working with high-resolution spectroscopy (HRS). Since then, atmospheric characterization with HRS has taken off and proven to be an invaluable tool not only to discover species (a dozen molecules and two dozen atoms detected), but also to measure their abundances and the atmospheric temperature – with precision similar to that now seen from JWST.

Now that JWST has launched, we are experiencing the first wave of exceptional measurements, which are indeed revolutionizing some of earlier expectations about the chemistry of gas giants and have begun to venture into the characterization of smaller and cooler planets. A similar revolution is expected after first light from the Extremely Large Telescope (ELT) at the end of the decade.

In light of these opportunities, it is time to strategically reassess the role of HRS in the next 5-10 years. What can we learn from combining HRS with JWST observations, and how can the two techniques best complement each other? How should we prepare for the ELT, such that we are ready to fully exploit its power from first light onward? Our original motivation to bring together the planet and stellar communities is now stronger than ever, as understanding the influence of stars in exoplanet measurements is already paramount, and will be even more important in the ELT era.

It is time to come together again, discuss the present and future of HRS, and place the technique in the landscape of JWST’s transformational science. We aim to do so with our second meeting – 2 HoRSES. So saddle up and come along for the ride in the summer of 2024!