Descripción del proyecto
Nuevos métodos de análisis de datos contribuyen a distinguir los exoplanetas de la actividad estelar
El método de la velocidad radial es uno de los más eficaces a la hora de localizar planetas extrasolares, y uno de los más directos para medir sus masas. El factor que más limita la sensibilidad del método es la actividad estelar, la cual puede inducir ruido en el espectro estelar observado. El proyecto financiado con fondos europeos GPRV se basó en métodos nuevos de análisis de datos capaces de diferenciar entre la actividad solar y los exoplanetas y estudiará los datos ya obtenidos por los instrumentos HARPS y HARPS-N, y los datos que genere próximo Terra Hunting Experiment. El proyecto ampliará los conocimientos que se poseen sobre la actividad estelar de distintos tipos de estrellas y podría sacar a la luz planetas no descubiertos en análisis anteriores. Sin duda allanará el camino para la nueva generación de estudios de la velocidad radial destinados a detectar planetas similares a la Tierra en torno a estrellas cercanas.
Objetivo
Radial velocity (RV) planet searches are a key exoplanet detection method, and one of the only ways to measure a planet's mass. The best RV instruments today reach precisions well below 1 m/s, something which would have seemed impossible 30 years ago. The key factor limiting the sensitivity of RV surveys now is stellar activity. Regions of enhanced magnetic flux on the stellar surface alter the shape of absorption lines in the stellar spectrum, and perturb the measured RVs. I have developed physically motivated but flexible, data-driven methods to disentangle planets from activity in RV data, which are critical to the success of future surveys. I now propose to apply these state-of-the-art techniques to the very large sample of multi-epoch spectra collected by HARPS and HARPS-N, the leading RV spectrographs of the past decade, and then to the forthcoming Terra Hunting Experiment (THE), which will use a copy of HARPS on a dedicated telescope to search for Earth-analogues around nearby stars.
The combined HARPS(N) archives are a treasure trove of information on activity-induced perturbations to spectra and RVs, which is currently under-exploited. This project have a transformative effect on our understanding of different types of activity effects, their dependence on stellar properties, and their signatures in the spectra and RVs. It will reveal planets that were missed by previous analyses, particularly around active (young) stars. Finally, it sets out a clear route to the efficient mitigation of activity effects that the THE survey requires to achieve its goals. THE will discover some of the best exoplanet characterisation targets for the next 15-20 years, and my ERC-funded team will be central to its success.
Programa(s)
Régimen de financiación
ERC-COG - Consolidator GrantInstitución de acogida
OX1 2JD Oxford
Reino Unido