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ABOUT ME

POSITIONS

Warwick Prize Fellowhip

PDRA in High Precision Radial Velocity

Dennis Sciama non-stipendiary Junior Research Fellowship

PDRA in exoplanet discovery with the PLATO mission

SCIENTIFIC INTERESTS

  • Exoplanets
  • Planets detection
  • Transiting planets
  • High-precision spectroscopy
  • Gaussian Processes
  • Bayesian data analysis
  • Numerical astrophysics
  • Hydrodinamical simulations

PUBLICATIONS

I am first author of ten papers in peer-review journals, they are described briefly here:

  • TOI-837 is a 35-million-year star hosting the transiting exoplanet TOI-837b, with an 8.32-day orbital period. We determined that TOI-837b has a radius of 0.82 Jupiter radii. We obtained an unexpected Doppler semi-amplitude of 35 m/s, indicating a planetary mass of 0.39 Jupiter masses. Our findings suggest TOI-837b has a substantial core of about 70 Earth masses, constituting approximately 60% of its total mass, challenging existing core formation models. Learn more about this story and how to be sure that your Gaussian Process is not overfitting at Barragán et al., 2024, MNRAS, in press..
  • REPUBLIC corrects systematics that vary between cameras while preserving true stellar signals common to all cameras. Drawing a parallel to the philosopher Plato, who sought to uncover underlying truths, REPUBLIC aims to reveal genuine astrophysical signals obscured by instrumental noise. This algorithm, like Plato’s inquiries, distinguishes reality from distortion, representing a significant advancement in stellar signal extraction. REPUBLIC has the potential to complement existing correction strategies for multi-camera surveys, pending further validation with PLATO mission data. See all the elegant maths in Barragán, Aigrain and McCormac, 2024, RASTI, 3, 198.
  • K2-233. By reanalyzing HARPS data of K2-233, which hosts three transiting planets, I applied a multidimensional Gaussian process regression to both radial velocity and activity indicators. This approach significantly improved the precision of the planetary signal measurements. I found new mass estimates for K2-233 b, c, and d to be 2.4, 4.6, and 10.3 Earth masses, respectively. These findings make K2-233 d an exciting target for transmission spectroscopy with the JWST. K2-233's system, with two inner planets below the radius valley and one outer planet above it, provides an excellent case for comparative studies on planet formation, migration, and atmospheric evolution. Barragán et al., 2023, MNRAS, 522, 3458.
  • HD 73583 (a.k.a TOI-560) is young (~750 Myr) planetary system containing two transiting mini-Neptunes with radii of 2.8 and 2.4 R_Earth for HD 73583 b and c, respectively. We measured masses the mases to be 10 M_Earth for both planets. The density ratio of both planets is unexpected in a photoevaporation scenario. This makes this system challenging for theorists and observers who have to search for atmospheric-loss signatures. If you want to know all the details about this interesting young system, check this post and Barragán et al., 2022, MNRAS, 514, 1606.
  • pyaneti II is an extension to the original pyaneti code. It has the same capabilities as pyaneti, but this new version has several improvements. This new release has a special emphasis on the modelling of stellar signals in radial velocity time-series. The code has a built-in multi-dimensional Gaussian process approach to modelling radial velocity and activity indicator time-series with different underlying covariance functions. If you want to learn more about the black magic in this code go and see Barragán, Aigrain, Rajpaul and Zicher, 2022, MNRAS, 509, 866.
  • K2-100b is a 3.8 R_Earth planet transiting a star member of the young Praesepe cluster (700–800 Myr) each 1.67 days. We performed a detailed analysis of HARPS-N radial velocity observations and we detected the planet signal in the activity-dominated radial velocity timeseries of the star. This is the first mass measurement for a transiting planet in a young open cluster. Its atmosphere is currently evaporating, this puffy young planet that will teach us a lot about photoevaporation. Learn more about this interesting system in this blog or go directly to check Barragán et al., 2019, MNRAS, 490, 698.
  • pyaneti is a multi-planet radial velocity and transit fit software. The code uses Markov chain Monte Carlo (MCMC) methods with a Bayesian approach and a parallelized ensemble sampler algorithm in Fortran which makes the code fast. It creates posteriors, correlations, and ready-to-publish plots automatically, and handles circular and eccentric orbits. It is capable of multi-planet fitting and handles stellar limb darkening, systemic velocities for multiple instruments, and short and long cadence data, and offers additional capabilities. Learn more about this awesome, fast and totally open source code in Barragán, Gandolfi, and Antoniciello, 2019, MNRAS, 482, 1017.
  • K2-141 b is a rocky planet which orbit its star each 6.7 hours! This Ultra-Short-Period (Period shorter than 1 days) Super-Earth is the shortest-period planet known to date with a precisely determined mass. Learn more about this planet in Barragán et al., 2017, A&A, 612, A95.
  • K2-139 b is a planet with a size similar to Jupiter, but with a third of the Jupiter mmass. This buddy orbits its star each 29 days! You can find the technical details in Barragán et al., 2017, MNRAS, 475, 175
  • K2-98 b is a Neptune-size planet with a density similar to Neptune. The planet orbits its star each 10 days. We calculated that the planet will be engulfed by its host star in 3 Gyr. The discovery is reported in Barragán et al., 2016, AJ, 152, 193

I am coauthor of tens of peer-review papers with more exciting exoplanet related discoveries. You can find my whole list of my publications here.

EDUCATION

Dottorato in Fisica e Astrofisica - Ph.D. in Physics and Astrophysics

Maestría en Ciencias (Astrofísica) - M.Sc. in Astrophysics

Licenciatura en Física - B.Sc. in Physics

REFEREE SERVICES

I have been refereed in the following journals and review cometees:

  • Nature Astronomy (Nat. Astron.).
  • The Astronomical Journal (AJ).
  • Astronomy & Astrophysics (A&A) and Astronomy & Astrophysics Letters (A&AL)
  • Montly Notices of the Royal Astronomy Society (MNRAS).
  • Internal reviewer of PLATO on-ground data processing documents.
  • OPTICON-TAC external science reviewer.
  • ING PATT external science reviewer.
  • Canadian Time Allocation Committee (CanTAC) external science reviewer.
  • The Journal of the Korean Astronomical Society (JKAS).
  • Astrophysics and Space Science (ASTR).

TEACHING EXPERIENCE

  • Organiser and teacher of the astronomy school "De exoplanetas y otros demonios", December 2019, Bucaramanga, Santander, Colombia.
  • Main supervisor of one master student in the Universidad de Guanajuato, Mexico, 2020-present.
  • Co-supervisor of two master students in the University of Turin.
  • Co-supervisor of two master students in the University of Oxford.

LANGUAGE SKILLS

  • Spanish (Native)
  • Italian (Fluent)
  • English (Fluent)

EXPERIENCE IN ASTRONOMY

  • 60 nights of observational experience: Multi-band photometric observations at the 2.1 m telescope in San Pedro Mártir, Ensenada, BC, Mexico (3 nights). High-resolution spectroscopic observations with FIES at the 2.58 m Nordic Optical Telescope, La Palma, Spain (3 nights). High-resolution spectroscopic observations with HARPS-N at the Telescopio Nazionale Galileo (TNG) at La Palma, Spain (5 nights). High-resolution spectroscopic observations with HARPS at the ESO La Silla 3.6m telescope, La Silla, Chile (49 nights in 8 runs).
  • Theoretical experience: Theoretical and numerical simulations of fluid physics in astronomy, using classical, relativistic, and general relativistic hydrodynamics. Simulations of relativistic jets by using a GRMHD module written by myself. Circumstellar disks simulations by using the state-of-the-art code FARGO3D, I created the setup, the 3D visualization tool and data interpretation.
  • Data analysis: Simultaneous transit and radial velocity modelling of photometric and spectroscopic data using the Levenberg-Marquardt algorithm and Marcov chain Monte Carlo simulations (Metropolis-Hastings and stretch move algorithms). Experience calculating age, metallicity, reddening, and distance of Open Cluster using BVRI multi-band photometry.
  • Data reduction: Reduction of echelle spectra from FIES@NOT.

COMPUTER SKILLS

  • OS: Linux/Unix (Ubuntu, Fedora), Windows.
  • Programming: git and the web repository github, FORTRAN, C, python and parallel computing with OpenMP and MPI.
  • Scientific software: IRAF, supermongo, Paraview, gnuplot, R, Mendeley, LaTeX, topcat, IDL.
  • Codes with astronomical application: FARGO3D, mercury, CASA.
  • Others: Microsoft Office, Libre Office, WPS Office, inkscape, vi, texmaker, stellarium.

OUTREACH EXPERIENCE

  • Online outreach contributions here
  • Participant in Outreach activities organised by the University of Oxford (Jan 2019 - present).
  • Invited to outreach talks in different events in different countries (e.g., Pint of Science in UK, Astronomy on Tap in Sweden).
  • More than 20 outreach astronomical activities. They include conferences and activities with telescopes, these events have been organized by a collaboration between the University of Guanajuato with different institutions such as Noche de las Estrellas Nacional and Mi Barrio Modelo.
  • Invited by different institutions in Mexico for outreach talks such as Centro de Investigaciones en Matemáticas (CIMAT) and Universidad Autónoma de Aguascalientes.

PERSONAL INTERESTS

When I am not searching for other planets, I am enjoying the serendipities of this one. As well as stars, the other things that I like are...

  • Sports: football, mixed martial arts, squash, running, street workout
  • Music
  • Classical and Sci-fi literature
  • Art cinema
  • Dinosaurs
  • Tango dancing
  • Photography