Hi, I’m José

I am an astronomer.

I am currently in my final year of PhD at Instituto de Astrofísica e Ciências do Espaço (IA) in Porto, looking for Earth-sized exoplanets.

I determine their mass and radius to understand their composition.

When a planet passes in front of a star, it hides part of the stellar surface, causing a dip in brightness. This is called a transit. The bigger the planet, the deeper the dip. By monitoring the brightness of stars, we can measure the size of exoplanets.

When we say “a planet orbits its star”, we mean “both objects orbit around their common center of mass”. This causes the star to wobble. Using spectrographs, we can detect this motion and determine the mass of the planets. This is called the radial velocities method. We use it to measure the mass of exoplanets.

Combining both transits and radial velocities, we are able to determine the density of exoplanets and understand what they are made of.

However, stars are active. This activity drowns out the signal coming from the exoplanets. We need to mitigate stellar activity to detect and characterize Earth-size exoplanets. This is what my research is about.