Mariana Villamil Sastre

PhD Student at Kapteyn Astronomical Institute .
University of Groningen, The Netherlands.
Interest on exo/planetary geophysics, geodynamics and atmospheres.
Astrophotographer junior

Research projects

3D simulations on Enceladus ice shell

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.

3D simulations on Enceladus ice shell

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 same time.

3D simulations on Enceladus ice shell

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 for CDE’s

3D simulations on Enceladus ice shell

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.

DEI Leadership

3D simulations on Enceladus ice shell

I've been always interested on helping the astronomical community in my country to develop and expand to territories with underrepresented communities. For this, I joinned the Colombian Network of Astronomy Students (RECA), which is an association that aims to create spaces that allow the exchange of ideas and significant experiences among its members, where we work for the realization of various academic and social impact projects. One of these projects that I'm involved in as an orginizing committee member, is the Mentorship program. A program designed to help BSc. students to get into a gradutate program and guide them with the application process in a 1-1 weekly meetings. With the mentors being colombian astronomers working on highly recognized institutions all around the world. Currently, we've a grant from the International Astronomical Union (IAU), for continue with the work on the program.

3D simulations on Enceladus ice shell

Also, following this line of DEI activities, I'm part of the Colombian Network of women working in astroscience (CHIA) by its initials in spanish. In this group we are working for make more visible the work done by colombian women researchers, and try to reduce the gender gap in academia. Specially, in astronomy. In this scenario, we have worked in several activities such as divulgation events, census, collaborations with other women associations in Latinamerica and now we're working to stablish a relationship between CHIA and the Ministry of Science to stablish new gender-equality policies on science. The image on the left is a report that we got in 2020 in a national newspaper -El Colombiano- talking about the network, the work done and future projects.

Astrophotography gallery

Astronomy is my passion, I have always oriented my academic interests towards the investigation of the universe. A few years ago, I discovered that astrophotography was both an artistic and empirical hobby that I fell in love with. As a gift, I received my first professional camera hoping to capture the Milky Way Center with my own techniques. Today I can say that I made it!. All my photo gallery take place in different landscapes in Colombia and has received recognition from entities such as the Bogota Planetarium!


Embalse del Sisga

Guayabal de Síquima

Embalse del Neusa

Bogota City

Solar eclipse

About me

Astronomy has interested me deeply since I was a child. With this in mind, I started my undergraduate program in Physics. Then, I began to feel extremely passionate about studying the planets and how they could help me to understand the formation and evolution of the solar system and conditions to harbor life there. My favorite hobbies are photography, camping, hiking and traveling all around the world.