«Pinchando» a la estrella: cómo un planeta desnudo ayuda a buscar aire exprés
Escuchar a escondidas la atmósfera de un planeta lejano se ve obstaculizado por el ruido de la estrella. En el sistema TRAPPIST-1 los astrónomos utilizaron un planeta-«micrófono»: TRAPPIST-1 b, un vecino sin aire que solo graba interferencias. Al restar esta grabación de la señal del planeta TRAPPIST-1 e, se puede aislar la voz limpia de su atmósfera.
Las primeras observaciones con el James Webb demostraron que la idea es correcta: en días tranquilos no se ven rastros de aire, como era de esperar. Pero los caprichos de la estrella siguen jugando al teléfono descompuesto. La búsqueda de atmósfera en TRAPPIST-1 e continúa, con la esperanza de pillar a la estrella de buen humor.
Resumen original
tal como lo escribieron los autores, en inglés arXiv:2512.07695
One of the forefront goals in the field of exoplanets is the detection of an atmosphere on a temperate terrestrial exoplanet, and among the best suited systems to do so is TRAPPIST-1. However, JWST transit observations of the TRAPPIST-1 planets show significant contamination from stellar surface features that we are unable to confidently model. Here, we present the motivation and first observations of our JWST multi-cycle program of TRAPPIST-1 e, which utilize close transits of the airless TRAPPIST-1 b to model-independently correct for stellar contamination, with the goal of determining whether TRAPPIST-1 e has an Earth-like mean molecular weight atmosphere containing CO$$_2$$. We present our simulations, which show that with the 15 close transit observations, we will be able to detect this atmosphere on TRAPPIST-1 e at $$\Delta\ln\,Z=5$$ or greater confidence assuming we are able to correct for stellar contamination using the close transit observations. We also show the first three observations of our program. We find that our ability to correct for stellar contamination can be inhibited when strong stellar flares are present, as flares can break the assumption that the star does not change meaningfully between planetary transits. The cleanest observation demonstrates the removal of stellar contamination contribution through an increased preference for a flat line over the original TRAPPIST-1 e spectrum, but highlights how minor data analysis assumptions can propagate significantly when searching for small atmospheric signals. This is amplified when using the signals from multiple planets, which is important to consider as we continue our atmospheric search.
El sistema TRAPPIST-1 es tan compacto que todos sus planetas cabrían dentro de la órbita de Mercurio. Un año en TRAPPIST-1 e dura solo 6 días terrestres.