activity
20242026
collaborators

17 papers

astro-ph.EP2026

Leveraging Impact Parameter to Mitigate the Transit Light Source Effect: Early Insights from TRAPPIST-1

Ana Glidden, Alexander I. Shapiro, Sara Seager +19

Stellar activity complicates exoplanet transmission spectra, particularly for smaller planets around M dwarfs with JWST. The transit light source (TLS) effect, the imprinting of sp…

astro-ph.EP2026

JWST-TST High Contrast: First Direct Spectroscopy of GJ 504 b reveals Clouds and Possible Metal Enrichment

Aneesh Baburaj, Jean-Baptiste Ruffio, Marshall Perrin +27

Characterizing the coldest directly imaged companions through direct spectroscopy has only recently become possible with the James Webb Space Telescope. We present moderate-resolut…

astro-ph.GA2026

The Dyson Minds 2025 Workshop: SETI around Black Holes

Olivia Curtis, Van Hunter Adams, Daniel Angerhausen +9

The Dyson Minds 2025 Workshop, held at the Center for Brains, Minds & Machines at MIT and organized by Penn State, MIT, and The Ultraintelligence Foundation, brought together resea…

astro-ph.EP2026

Direct Images of CO2 Absorption in the Atmosphere of a Super-Jupiter: Enhanced Metallicity Suggestive of Formation in a Disk

William O. Balmer, Laurent Pueyo, Ashley Messier +15

It is unclear how directly imaged substellar companions with masses near the deuterium burning limit form, because these objects are rare and their bulk properties are not diagnost…

astro-ph.SR2026

Overestimated Pressure Broadening Misleads Model Spectra in Cool M Dwarf Stars

Ana Glidden, Veronika Witzke, Alexander I. Shapiro +1

Available one-dimensional stellar models fail to reproduce the observed spectrum of the ultracool M dwarf TRAPPIST-1. In particular, current models predict strong iron hydride (FeH…

astro-ph.SR2026

Molecular hydrogen controls the temperatures of flares on TRAPPIST-1

Alexander I. Shapiro Nadiia Kostogryz Sara Seager Veronika Witzke Julien de Wit Valeriy Vasilyev Astrid M. Veronig Robert Cameron Hardi Peter Sami K. Solanki

Early JWST observations of TRAPPIST-1 have revealed an unexpected puzzle: energetic white-light flares ( erg) reach temperatures of only 3500--4000\,K, ne…