Name Affiliation Title Abstract Combined and simultaneous observations of high-precision photometric time-series acquired by TESS observatory and Comprehensive high-stability, high-accuracy measurements from Analysis of ESO/HARPS telescope allow us to perform a robust stellar Simultaneous magnetic-activity analysis. We retrieve information of the Photometric and Eliana Max Planck Institute photometric variability, rotation period and faculae/spot Spectropolarimetric Amazo- for Solar System coverage ratio from the gradient of the power spectra method Data in a Young Gomez Research (GPS). In addition magnetic field, chromospheric activity and Sun-like Star: radial velocity information are acquired from the Rotation Period, spectropolarimetric observations. We aim to identify the Variability, Activity possible correlations between these different observables and & Magnetism. place our results in the context of the magnetic activity characterization in low-mass stars. Asteroseismology is a powerful tool for probing stellar interiors and has been applied with great success to many classes of stars. It is most effective when there are many observed modes that can be identified and compared with theoretical models. Among evolved stars, the biggest advances have come for red giants and white dwarfs. Among main-sequence stars, great results have been obtained for low- mass (Sun-like) stars and for hot high-mass stars. However, at intermediate masses (about 1.5 to 2.5 ), results from the large number of so-called delta Scuti pulsating stars have been very disappointing. The delta Scuti stars are very numerous (about 2000 were detected in the Kepler field, mostly in long-cadence data). Many have a rich set of pulsation modes but, despite years of effort, the identification Asteroseismology of the modes has proved extremely difficult. One problem is of High-Frequency Tim Bedding University of Sydney that only a seemingly random subset of possible modes are Delta Scuti Stars excited, making it difficult to identify a regular pattern. This with TESS is compounded by rapid rotation and by the low radial orders, both of which tend to spoil the regularity. TESS observations have finally led to a breakthrough. We have focussed on the higher-frequency delta Scuti stars (above about 30 c/d), since these seemed to offer the best hope for identifying regular patterns. The large set of TESS short-cadence light curves are ideally suited to this. We have been able to identify dozens of delta Scuti stars with very regular pulsation spectra. For the first time, we can identify the modes (assigning n and l values) and compare the frequencies with theoretical models. These results will enable TESS to open up intermediate-mass stars to the power of asteroseismology, allowing us to place strong constraints on masses, ages and internal rotation. We are currently preparing a paper for Nature or Nature Astronomy. Francois Geneva Observatory Mass Measurement TESS follow-up efforts using high-precision spectrographs Bouchy with ESPRESSO of are ongoing to characterize transiting planets with radii below Rocky Worlds , however still with a limited scope: only the more Detected by TESS massive planets on shorter-period orbits are amenable to robust mass measurements. ESPRESSO is the new highly- stabilized and high-resolution spectrograph in operation at ESO/VLT since last September. ESPRESSO represents a breakthrough in this field: its 2-magnitude gain and improved radial velocity precision with respect to HARPS-like instruments allows a thorough exploration of the rocky world population with radii below detected by TESS. We will present an overview of the ESPRESSO performances, describe the TESS targets selected for the ESPRESSO Guarantee Time Observing program, and the first results obtained. In a search for timing anomalies in previously known hot Jupiter systems, one object has stood out: WASP-4b transited seconds earlier than expected, based on data stretching back to 2007. Its orbital period also appears to be shrinking, by milliseconds per year. The period change could be caused by tidal orbital decay, apsidal precession, or the gravitational influence of a third body. The Early Arrival Luke Bouma Princeton University Confirming whether any of these processes are at work would of WASP-4b be interesting because it would teach us about the forces that govern the lives and potentially ultimate fates of hot Jupiters. Though more data are needed to understand the specific case of WASP-4b, further TESS observations should enable broader timing studies of the hot Jupiter population. Such studies will likely improve our understanding of both planet- planet and planet-star interactions. Almost all massive stars inevitably end their lives in a violent supernova explosion and form a black hole or neutron star. Supernovae enrich the interstellar medium with chemical elements and impact the next generation of star formation and the evolution of their host galaxy. However the mass of the compact remnant and the supernova chemical yield depend strongly on the internal physical properties of the progenitor star, which are currently not well-constrained from observations. The large theoretical uncertainties in the models of massive star interiors accumulate throughout stellar evolution, with the lack of a robust theory of stellar structure and evolution being particularly pertinent for evolved massive stars such as blue supergiants. Asteroseismology of stellar Low-Frequency oscillations allows us to uniquely probe stellar interiors, yet Gravity Waves in Instituut voor inference from massive stars has been limited by a dearth of Dominic M. Massive Stars Sterrenkunde, KU detected pulsations in such stars until recent space photometry Bowman Revealed by High- Leuven missions. In this talk, I report on the diverse pulsational Precision K2 and variability discovered in a large sample of massive stars TESS Photometry. observed by the K2 and TESS space missions. The discovery of coherent pulsation modes and stochastic low-frequency gravity waves in numerous blue supergiants allow the interior properties of massive stars to be mapped from the main sequence to the later stages of their evolution. Asteroseismic modelling provides important constraints on ages, core masses, interior mixing, rotation and angular momentum transport, which are essential input parameters in stellar evolution models. The discovery of pulsational variability in space photometry of blue supergiants provides a necessary first step towards a data-driven empirical calibration of theoretical evolution models for the some of most massive and short-lived stars in the Universe. Derek Florida Gulf Coast Light Curves for The 30-minute cadence full-frame images collected by TESS Buzasi University Asteroseismology during the nominal mission provide an invaluable resource for from Full-Frame science ranging from stellar astrophysics to exoplanets. Images Drawing on the Kepler experience, the TESS Asteroseismic Science Consortium (TASC) has formed a collaborative effort to use TESS data for asteroseismology, and established a TESS Asteroseismic Science Operations Center (TASOC) to produce light curves from full-frame images. In this talk, we will present the TASOC pipeline for producing light curves from full-frame images, including light curve extraction from the FFIs, light curve correction for instrumental effects, automated stellar variability classification, and verification of absolute time for the resulting photometry. We will describe the TASOC FFI data releases for the first TESS sectors which include millions of light curves down to Tmag<15, and present comparisons of TASOC FFI light curves to other community-driven efforts such as image-subtraction and the eleanor pipeline. Finally, we will highlight a broad range of asteroseismic detections across the HR diagram enabled by FFI light curves. Theron Harvard University Using TESS to Brown dwarfs are defined as objects with masses between 13 Carmichael Understand the and 80 times the mass of Jupiter. These limits are somewhat Brown Dwarf arbitrarily chosen to be the mass at which deuterium fusion Population takes place ( ) and the mass at which hydrogen fusion takes place ( ). Though motivated by physical processes, these mass limits—particularly the lower mass limit—do not provide much insight on the formation mechanisms of the objects at these masses. To better understand brown dwarf formation mechanisms, we look to the brown dwarfs that orbit main sequence stars to examine their physical and orbital properties. Brown dwarfs that transit stars are quite rare with only 19 published and so we seek to find more like these with the transit method. Given the nature of the internal pressure support mechanisms of brown dwarfs (electron degeneracy pressure), we expect them to be between at least the size of Saturn and Jupiter, but they may be even more inflated if they are younger than a few million years. This means that for most main sequence stars and even stars that are slightly evolved, the transit depths produced by brown dwarfs will be well within the sensitivity of the premier transit survey mission for the next decade: the TESS mission. Additionally, because it is fully sensitive to short- period brown dwarfs that transit bright stars during its primary mission, TESS is well-suited to characterizing a parameter space of the brown dwarf population that has very few known objects. Transit light curves allow us to calculate a brown dwarf’s radius while we rely on follow up spectra