Letters of Intent received in 2019

LoI 2021-2072
Transiting Exoplanets and their Atmospheres in the Era of James Webb Space Telescope

Date: 22 March 2021 to 26 March 2021
Location: Marrakech, Morocco
Contact: zouhair Benkhaldoun (zouhair@uca.ma)
Coordinating division: Division F Planetary Systems and Astrobiology
Other divisions: Division B Facilities, Technologies and Data Science
Co-Chairs of SOC: zouhair Benkhaldoun (Cadi Ayyad University, Oukaimeden Observatory)
Andrew Szentgyorgyi (Harvard-Smithsonian Center for Astrophysics)
Co-Chairs of LOC: zouhair Benkhaldoun (Cadi Ayyad University, Oukaimeden Observatory)
Ismael Moumen (Laval University)
Jabiri Abdelhadi (Cadi Ayyad University, Oukaimeden Observatory)



1. Detection of exoplanets transiting bright nearby stars
2. Advances in exoplanet atmosphere theories and observation
3. State-of-the-art analysis techniques in time-series spectrophotometry from space
4. Biosignatures and habitability.
5. An overview of exoplanets from the ground based telescopes
6. Exoplanets observed from space (Mainly from JWST, TESS & CHEOPS and their first expected data)



Among the thousands of known exoplanets, the few of them that transit bright nearby stars have had the highest impact on our overall understanding of the large planetary population hosted within our galaxy because their detailed characterization (mass, size, orbit, atmosphere, obliquity, etc.) is within reach of current technology. Notably, the last decade saw the first observational constraints on the atmospheric properties of short-period planets transiting nearby stars, including the first firm detection of molecular signatures in exoplanetary atmospheres. These pioneering studies performed with space and ground-based instruments have provided initial glimpses at the atmospheric chemical composition, vertical pressure-temperature profiles, albedos, and circulation patterns of extrasolar worlds.
The next major step in this field is undoubtedly the upcoming launch of the James Webb Space Telescope (JWST), the Transiting Exoplanet Survey Satellite (TESS) and CHaracterising ExOPlanet Satellite (CHEOPS) that will offer an unprecedented potential for the study of these nearby transiting exoplanets. JWST is particularly important, since it will provide large aperture, a heliocentric orbit, and continuous wavelength coverage from 0.6 to 28 microns. It should be powerful enough to make possible detailed atmospheric characterization not only of hot Jupiters but also of planets of smaller size and more temperate, even including some terrestrial planets recently found orbiting in the habitable of nearby very-low-mass red dwarfs. Its spectral coverage and high-precision should enable measuring the abundances of key molecules by transient spectroscopy, and to place tight constraints on atmospheres’ vertical and horizontal structures by occultation and phase curve spectroscopy. It will be able to characterize a large diversity of planets in terms of mass, size, irradiation, and host star properties. Its observations of transiting exoplanets will bring tight constraints on current theories of planets formation, evolution, and, to some extent, habitability. For example, with JWST we will be able to address how the atmospheric properties of giant planets vary with their masses or with the spectral type and activity of their host star; the nature and origins of high-altitude clouds identified by transmission spectroscopy in several short-period planets’ atmospheres; and the actual nature of low-density super-Earths (aka mini-Neptunes). The three space missions, together, will provide the context and data sets for the coming generation of ground based, extremely large telescope that will start science operations in the 2025 time-frame.
The purpose of this proposed IAU Symposium is to bring together the observational astronomers, especially those interested in using JWST to perform detailed atmospheric characterization of transiting planets or involved in transit search programs focused on finding new potential targets for JWST, and the theoretical astronomers aiming to constrain their theories with JWST observational results. Invited talks and reviews will cover both the observational and theoretical sides, the ultimate goal of the symposium being to optimize the communication between the experts of both sides, and thus to maximize the scientific return of JWST on our understanding of exoplanet atmospheres. The Symposium will cover a broad range of topics within a 5-day program (including half-day excursion).
We suggest to host this symposium in Marrakech (Morocco) for different reasons:
● Historical: Founded in 1062, Marrakech is one of the most important of Morocco's four former imperial cities;
● Cultural: Every year, Marrakech hosts big musical, cultural conferences and seminars. The last major conference was the United Nations Climate Change Conference (The 22th Conference of the Parties, COP 22) in November 2016 with the participation of 197 countries;
● Educational: Marrakech hosts Cadi Ayyad University, considered as the best university in Morocco and one of the best French speaking universities in Africa.
● Scientific: Cadi Ayyad University have ambitious goal to be a positive player in the astrophysics community. It is the only university in North Africa possessing a modern astronomical observatory (5 small telescopes) and an active research program dedicated to solar system small bodies and exoplanets researches;
● Geographical : Morocco is almost located at the same distance from America, Europe, other countries in Africa and Asia.
Morocco has organized many events sponsored and endorsed by the international astronomical union. For example, Morocco hosted two internationals schools for young astronomers (ISYA) in 1990 at Marrakech and 2004 at Ifrane an IAU technical workshop (Astronomical Site Evaluation in the Visible and Radio Range in 2001. The publications of the meeting were edited by IAU . Finally, Marrakech hosts the observatory of Oukaïmeden. Located at 2,750 meter above the sea level, this observatory is hosting 5 small telescopes (MOSS, OWL-Net, KACCOLR, OUCA and TRAPPIST-North) dedicated to solar system small bodies, variable stars and exoplanets researches. Since 2010, Cadi Ayyad University is focused on the thematic of exoplanets and was part of the discovery of the TRAPPIST-1 exoplanet system in 2016 . The organization of the symposium in Marrakech will allow giving an even bigger impulse to this thematic in Morocco.
Since the James Webb Space Telescope will be launched in 2021 and we will have on hand about 3 years of data from TESS, 2021 will be time for an International Astronomical Union (IAU) Symposium on the topics of exoplanets and their atmospheres in the era of JWST. Therefore, our proposed symposium will be the first opportunity to address the stat of the art about data expected from the JWST. We suggest to hold the Symposium in Marrakech, Morocco from 22 - 26 March 2021.
The initiative of the symposium originates from newly formed Arab Astronomical Society (ArAS) which aspires to the development of astrophysics in the Arab countries. The candidates selection process for the symposium grant will apply gender rules as well as regional diversity of IAU.
● Benkhaldoun Zouhair (Oukaimeden Observatory, Morocco)
● Andrew Szentgyorgyi (Harvard-Smithsonian Center for Astrophysics, USA)