Geodynamical regimes in Earth-like exoplanets: A parameter study for linking the internal structure with atmospheres
Solid-state convection of rocky planetary mantles is essential to a planet's habitability over geological timescales. The starting point of main events, such as plate tectonics,
is mainly controlled by this heat transfer efficiency. To understand better how this particular tectonic regime came about in Earth's evolution, and how this can be extrapolated
to our understanding of the dynamical regime of Earth-like exoplanets and especially their outgassing, it is necessary to investigate under which conditions Earth-sized planetary
mantles can produce enough melt that might deliver volatiles to the surface. In this study, I model the internal structure of Earth-sized exoplanets that serve as a basis for 2D
heat transfer numerical simulations to explore the parameter space of different silicate mantle sizes and dynamical regimes. In this way, I investigated the optimal candidates for
internal structure configurations and compositions, to break the primitive basaltic crust considering different heat sources. I applied my model to the particular case of the TRAPPIST-1
planets to constrain tidal dissipation that can be produced within their mantle according to different core sizes. I showed that Earth-like exoplanets with big cores are the best candidates
to produce melt efficiently and consequently deliver more water content to the atmosphere.
Mapping the Sun’s active regions from SDO images to HARPS-N solar spectra
Active regions are the main observable of magnetic activity in the Sun, these zones include structures such as faculae, sunspots and plage, the first two are located at the photosphere and the
third one at the chromosphere, respectively. The aim of this work was to perform an analysis to
determine if there’s any individual contribution to the relative spectra driven by Sun’s activity.
Besides that, correlate the disc-integrated spectra (HARPS-N) with the spot and plage filling factors measured with images taken by the Solar Dynamics Observatory (SDO). Using a previous
code (YAMORI, Cretignier et. al in prep), we found that there’s no clear evidence of sensitivity
to sunspot-faculae activity due to an interference pattern and systematics from the detector. Nevertheless, an equivalent of a stellar surface-tomography analysis was performed during the process
and it was possible to observe strong features in spectral lines affected by plage and spot at the
Searching for disintegrating planets in the TESS data
Catastrophically Disintegrating Exoplanets (CDEs) are Mercury-size rocky bodies that due to the
close distance with their host star, these planets can heat up to high temperatures, allowing the
sublimation of the planet’s surface. Only less than 10 exoplanet candidates has been confirmed as
CDE’s in the last 10 years. Taking into account that these planets have very short periods (4-30hr),
observations could miss/confused them with other big planet transits and stellar phenomena. In
this case, we are looking to identify this type of transits using light-curves from TESS telescope
data. Through the implementation of a pipeline, we can detect them in an automatically way,
we use an exponential model that considers a set of orbital parameters that are fit through an
optimization method. This one, was selected from three different routines tested during the work.
Finally, we evaluate the entire method in 500 systems from which we obtain a final list of candidates
2D/3D simulations for the episodic thermal convection on Enceladus ice shell
In this research we investigate how Enceladus,one of Saturn's most important moons maintains the heat observed by Cassini spacecraft.
The existence of an episodic thermal convection in the Enceladus crust is proposed, with numerical models of finite elements in spherical
coordinates, which include geodynamical parameters such as tidal forces, a non-uniform viscosity in the crust and a type of convection under
a layer not convective. In addition, it is included in the model that the convection is taking place episodically, giving rise to events of
maximum heat transport in a span of a few million years and a consequent stability, allowing that the high heat flow can be explained as the
release of heat stored in the past. The model is designed to obtain an energy value close to the data obtained by the Cassini mission.