ESA's Holland-Area Exoplanet Science Meeting (HAESM) 2022


Uniting all ESA and Holland-area exoplaneteers for a day of science, discussions, and collaboration.

Tuesday, 05 April 2022, 13:00 - 17:10 Holland time, online via WebEx





The welcome & institute overview talks will feature a big picture selection of research highlights and interests from the diverse group members at each place. The individual science talk abstracts can be found below:

Michiel Mien (SRON): Atmosphere retrievals in 3D - application to WASP-43b. The increasing completeness and accuracy of observations with, e.g., JWST and other future space missions force us to increase also the complexity of our retrieval models. No longer can we rely on simple one dimensional models to analyse the observed data. We present here a 3D retrieval framework capable of analysing observational data of transmission, eclipse and phase curve spectroscopy simultaneously. The setup is able to retrieve among others how heat is transported from the dayside to the nightside of the planet. We apply this to the HST phase curve of the well known hot Jupiter WASP-43b and show that the heat redistribution is consistent with predictions from GCM models.

Joe Callingham (Leiden): Radio stars and exoplanets at low-frequencies. One key question that astronomy is attempting to answer is whether there are habitable planets around stars other than our Sun. While we have entered an era where identifying nearby exoplanets has become standard, discerning whether the environmental conditions dictated by the host stars are suitable for life has proved far more elusive. The detection of low-frequency radio emission from an M dwarf or an exoplanet provides a direct probe of extrasolar space weather and the planet's magnetic field - information crucial for assessing the potential habitability of the planet. In this talk, I will outline our LOFAR survey of stellar systems, with a focus on our recent detection of strong, highly circularly polarised low-frequency radio emission associated with nearby stars - the expected signpost of star-exoplanet interactions. I will discuss how our survey represents the most comprehensive observations of stellar systems at low frequencies. I will conclude with our progress in determining the expected periodicity of the radio emission from star-planet interactions.

Sarah Kendrew (STScI): Transiting exoplanet science with JWST. At the time of writing this abstract we are 40+ days post-launch of the James Webb Space Telescope. Webb has a number of capabilities that are ideally suited for follow-up observations of transiting exoplanets that were discovered with other facilities.  A special category of observations, Time Series Observations (“TSOs”), has been defined to capture the specific needs of such observations, with special operational provisions and a dedicated path through the calibration pipeline. An exciting  I will give an overview of the operational concept for Time Series Observations, and the instrument modes that are available for these observations. I will also show the resources that have been developed at STScI to support the transiting exoplanet community.

Christian Ginski (Leiden): Results from the Young Suns Exoplanet Survey. We present the current status of the Young Suns Exoplanet Survey (YSES), a survey of 72 solar-mass members of the approximately 16 Myr-old Lower Centaurus-Crux subgroup of Scorpius-Centaurus (Sco-Cen). We have discovered three planetary mass companions at large projected separations from their stars: YSES 1b and c at 320 and 162 au respectively, the first directly imaged multiple planet system around a solar mass star, and YSES 2b, a 6 Jupiter mass companion at 115 au. The presence of these companions within the first third of the YSES sample suggest a relatively high detection rate above 10% for distant companions (>100au) of solar mass stars, and gravitational scattering of exoplanets from their original birthplaces, or possibly in situ gravitational instability, may be more common than previously thought. These exoplanets are also prime targets for characterisation and variability studies for both ground based observatories and the James Webb Space Telescope.

Laura Hayes (ESTEC): Solar flare effects on the Earth's ionosphere. Solar flares have a direct consequence on the ionized portion of the Earth’s atmosphere: the ionosphere. Solar X-ray and extreme ultraviolet (EUV) irradiances can increase by several orders of magnitude during a solar flare, driving enhanced ionization on the entire dayside ionosphere. This in turn results in increased electron density profiles of all regions of the ionosphere. Immediate, adverse space-weather effects of solar flares on the ionosphere include impacting high-frequency (HF) radio communications, GPS/GNSS navigation , air traffic control facilities, and low-Earth satellite orbits. In this short talk, I’ll discuss how we can utilize remote sensing observations of very low frequency (VLF) radio waves to probe the lower ionosphere in response to solar flare X-ray and EUV irradiances.

Fabienne Nail (Amsterdam): Revealing Anisotropic Evaporating Exoplanet Atmospheres. The hydrodynamic escape of atmospheres can have major implications for the evolution of close-in planets and has been proposed as an underlying cause of the observed lack of short-period Neptunes. We explore how the interaction between the planetary and stellar wind affects the properties of the observed He-1083 nm line. We focus on anisotropic atmospheric escape using 3D hydrodynamic simulations. We investigate how the stellar wind shapes the planetary outflows with varying degrees of day-night and equator-pole anisotropy and generate synthetic transmission spectra and light curves in the He-1083 nm line. For day-to-night anisotropic structures, we find an overall blue shift of the helium line center of a few km/s  compared to the isotropic case. Furthermore, we find a dependency of the blueshift on the degree of assumed anisotropy. These findings may enable identifying avenues for the characterization of asymmetric outflow geometries through helium observations.

Dimitrij Titov (ESTEC): Venus - an “exoplanet” next door. Venus appears to be an “alien” planet drastically and surprisingly different from the Earth. Space missions revealed the world with remarkably hot, dense, cloudy, and dynamic atmosphere filled with toxic species. The spacecraft delivered comprehensive data on the temperature structure, the atmospheric composition, the cloud morphology, the atmospheric dynamics, the solar wind interaction and the escape processes. In many respects Venus can be considered as an archetype of terrestrial exoplanets. The talk will review the current knowledge of Venus and outline strategy of its future exploration.

David Doelman (Leiden): Direct characterization of exoplanetary systems with advanced liquid-crystal coronagraphs. To directly image and spectroscopically and polarimetrically characterize exoplanets, the starlight and its halo needs to be suppressed by many orders of magnitude. We are developing advanced coronagraphic optics based on patterned liquid-crystal optics to enable such observations. Such components can impose virtually any phase pattern in a strictly achromatic fashion, and therefore facilitate extreme manipulation of optical wavefronts and PSFs, and enable fully optimized high-contrast imaging systems. We have installed our liquid-crystal coronagraphs at most of the large ground-based telescopes, and are performing the first L-band spectroscopic observations of exoplanetary systems like HR 8799. We are currently embarking on a technology development program for advanced liquid-crystal optics to meet the extreme demands of future space telescopes that will directly observe rocky exoplanets, and probe them for signs of life.

Kate Isaak (ESTEC): CHEOPS Opportunities. CHEOPS, the CHaracterising ExOPlanet Satellite, is the first in ESA's fleet of exoplanet missions. Taking the opportunity of the last spot of the meeting, I will introduce the mission and advertise the current observing opportunity available to scientists worldwide to exploit the unique capabilities of the mission.


WebEx Etiquette

  • Your screen name should be your full name followed by your institution in brackets, e.g. "Mae Carol Jemison (NASA)"
  • Keep your microphone muted to minimize background noise
  • Make use of the chat & participants menu
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  • Continue conversations with speakers in our Teams channel


Code of conduct

  • Participants will conduct themselves in a professional manner that is welcoming, inclusive, and free from any form of disrespect, intimidation, bullying, discrimination, harassment, and retaliation.
  • Participants will treat each other with civility and respect to create a collegial and professional environment where all voices and perspectives can be heard irrespective of biases, known and unknown. Creating a supportive environment is the responsibility of all participants.
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  • If a participant observes inappropriate comments or actions, intervention is appropriate if it respects all parties. Violations of the code of conduct may be reported to the SOC members listed on the Home page of this website, who will all be identified as co-hosts on the Zoom call.