Caleb Kenji Harada & Barak Rom

Talk 1: Caleb Kenji Harada, 3:00pm -  3:30pm
Precursor science for the Habitable Worlds Observatory: Pathways to planet properties
Searching for life on planets in the habitable zones (HZs) of nearby stars is a primary science objective of future space-based observatories with starlight suppression technology, e.g., the Habitable Worlds Observatory (HWO). In just two decades, HWO will survey nearby stars whose HZs are accessible via high-contrast direct imaging to discover 25 Earth-size exoplanets, and then measure the UV/Optical/NIR spectra of those planets with exquisite precision to detect biosignatures. Maximizing precursor knowledge of the best exo-Earth survey targets for HWO reduces mission design risk by enabling science and engineering trades to evaluate the impact of potential design choices and astrophysical realities on the expected yield of potentially-habitable planets that HWO will observe. System Properties and Observational Reconnaissance for Exoplanet Studies with HWO (SPORES) seeks to advance precursor and preparatory knowledge of the most promising star-planetary systems for the future HWO exo-Earth survey in order to optimize mission design, mitigate the risk of imposter exo-Earths, and enhance the scientific return of HWO in addressing broader questions in exoplanetary science. In this talk, I will present recent SPORES results investigating the current state of our knowledge about promising HWO target stars, and assessing the sensitivity of past radial velocity (RV) searches for planets around those stars. I will also highlight ongoing and future work to better understand the system architectures of these stars with ground-based imaging and PRV measurements and expand the sample of potential HWO targets. This work is supported by NASA ADSPS and NSF GRFP grants.

Talk 2: Barak Rom, 3:30pm -  4:00pm
Dynamics and transients around supermassive black holes
Most galaxies host a supermassive black hole (SMBH) at their center, surrounded by a dense cluster of stars and stellar-mass black holes. In this talk, we discuss how scatterings and gravitational wave emission shape the stellar distribution around these SMBHs, driving a range of transients such as tidal disruption events, X-ray quasi-periodic eruptions, and gravitational wave sources. Our focus will be on extreme mass-ratio inspirals — the mergers of stellar-mass black holes with SMBHs. We calculate their formation rate and predict the number of events that will be detectable by LISA, the upcoming space-based gravitational wave observatory.