Didier Queloz, Ph.D.

SCOL Project: Search for Habitable Planets Eclipsing Ultra-Cool Stars (SPECULOOS, part II)

The essence of my research work is about understanding planet formation and evolution through the detection and characterization of exoplanets. Its long-term perspective is to understand the origin, prevalence and nature of life. The main objective of the work supported by the Simons Collaboration on the Origins of Life is to carry out a comprehensive research program eventually leading to the detection of Earth-like planets amenable to life detection. The bulk of the Simons Foundation support in the past four years has been mostly dedicated to the development of a new facility (SPECULOOS) and, in particular, the installation of the Callisto telescope and the scientific exploitation of the Ultra Cool Dwarf Transit (UCDT) survey, with the goal of detecting orbiting Earth-size planets transiting cool dwarf stars.

The work investigating the impact of ultraviolet (UV) light on life building blocks stimulated new avenues for research, as well as a series of new questions related to this program. M stars are very attractive targets for detecting small transiting planets, on the basis of their small size and rather low temperature. In that respect, the TRAPPIST-1 planetary system is a good example, and GJ1132b as well. But in the view of the abiogenesis limits, planets in these systems don’t receive enough UV flux to produce the macromolecular building blocks of life. The element that remains uncertain is the quantitative assessment of the impact of flares frequently observed on coolest star M8-9 and below. In the renewal proposal, we are considering these new elements and are expanding the scope to the smallest stellar objects, and we include in our investigation the study of stellar contamination rising from the inhomogeneity of the stellar photosphere, which could potentially limit our capabilities to reliably measure planet atmospheres by transit spectroscopy of low-mass stars.

The proposal has the following scientific objectives:

1. Build up a comprehensive picture about other “TRAPPIST-1 systems” around nearby 500 brightest ultracool dwarfs. The exploitation of the SPECULOOS survey is the continuation of the initial proposal. It essentially aims to provide additional planet detection for follow-up with the James Webb Space Telescope. In addition, from a global analysis of the survey, we would obtain a robust statistical description of the planetary population orbiting these stars. An interesting byproduct of the survey is to gather information about the rate of flares and its impact on the abiogenesis limits for low-mass stars.

2. Expand the search for small planets to the lowest end of the main sequence at the boundary of brown-dwarfs limit (L-type spectral type). The detection of short-period transiting planet on such stars would provide us with even better targets for further atmospheric characterization with Webb. To detect them with the SPECULOOS facility, we would need to upgrade our detector and develop a new camera operating in the infrared. We are planning to study and develop such a camera.

Bio:
Didier Queloz is professor of physics at Cambridge Cavendish Laboratory and of astronomy at Geneva University (part time). He was at the origin of the “exoplanet revolution” in astrophysics in 1995, when during his Ph.D. work with his supervisor, Michel Mayor, they announced the first discovery of a giant planet orbiting another star outside the solar system. This seminal discovery spawned a revolution in astronomy and kick-started the field of exoplanet research. Over the next 25 years, Queloz’s scientific contributions have essentially been to make progress in detection and measurement capabilities of exoplanet systems with the goal of retrieving information on their physical structure to better understand their formation and evolution in comparison with our solar system. More recently he has been directing his activity to the detection of Earth-like planets and universal life. In the course of his career, he has developed astronomical equipment, new observational approaches and detection algorithms. He participated in and conducted programs leading to the detection of hundreds of planets, include breakthrough results. He has contributed to numerous articles, documentaries, movies, and TV and radio interviews to share excitement and promote interest for science in general and particularly exoplanets and life in the universe.

Queloz was awarded (with Michel Mayor) the 2011 BBVA Foundation Frontiers of Knowledge Award in Basic Sciences for developing the new astronomical instruments and experimental techniques that led to the first observation of planets outside the solar system, and he received (with Mayor) the 2017 Wolf Prize in Physics for the discovery of an extrasolar planet orbiting a star similar to the sun. He and Mayor also shared the 2019 Nobel Prize in Physics for the discovery.