Embedded Files
I am interested in exploring how physical, chemical, and dynamical processes in protoplanetary disks set the stage for planet formation. In particular, I investigate how volatiles are transported, processed, and preserved, using both high-precision observations (e.g. with JWST/MIRI, ALMA) and theoretical modeling. My work aims to establish links between disk evolution (thermal events, accretion, pebble drift, disk substructure) and the chemical/isotopic signatures found in planets and Solar System bodies. Ultimately, I seek to understand how early disk conditions imprint on emerging exoplanet compositions and what that tells us about planet diversity, including our own Solar System.
For a full list of my publications, you can look me up on ADS
Protoplanetary disk chemistry
Protoplanetary disk chemistry
I work in Prof. Ted Bergin’s group studying the chemistry of protoplanetary disks, focusing on the carbon-to-oxygen ratio (C/O) as a tracer of disk composition and planet formation. As part of the JDISCS collaboration, I use JWST-MIRI observations to investigate the evolution of inner disk chemistry. In Colmenares et al. (2024b), we analyzed DoAr 33, a T Tauri star with a hydrocarbon-rich disk, and found C₂H₂ emission consistent with carbon-enriched models (C/O≈2–4) inside the soot line. This likely results from carbon grain sublimation, supported by crystalline silicate detections.
We propose that this sustained hydrocarbon-rich chemistry around a solar-mass star results from the central star's unusually low accretion rate, which allows the carbon-rich chemistry from grain destruction to persist. To test this hypothesis, our JWST Cycle 4 program will target 14 disks spanning a wide range of accretion rates.
Thermal processing of pebbles
Thermal processing of pebbles
Solar System meteorites exhibit a fundamental isotopic dichotomy between non-carbonaceous (NC) and carbonaceous (CC) groups. The existence of this dichotomy hints at two separate reservoirs from which planets could accrete material during the formation of the Solar System. In Colmenares et al. (2024a), we studied how an accretion outburst can set a thermal gradient in the protoplanetary disk and impart an isotopic signature. We modeled how these two distinct reservoirs evolve, and found that the combination of viscous mixing and radial drift of the pebble populations is consistent with isotopic signatures in the current-day meteorites, specifically in supernovae-origin isotopes like 54Cr, 30Si,48Ca, among others. This contrasts the idea that Jupiter formed in-situ and served as a barrier between the two reservoirs.
Fig. 7 in Colmenares et al. (2024a)
Stellar accretion
Stellar accretion
Magnetospheric accretion is a key process in the formation of T Tauri stars, where material from the surrounding disk accretes onto the star's surface along magnetic field lines. It influences the stellar mass and rotation, but also plays a crucial role in the evolution of its protoplanetary disk. The study of magnetospheric accretion is essential for comprehending the interplay between stellar accretion and the development of planetary systems around young stars. During my undergrad, I studied the Hydrogen lines of accreting stars from UV X-shooter spectra to find a relation between the flux and the geometry of the magnetosphere. Most recently, Micolta et al. (2022) found that refractory abundances measured from accretion flows might reflect substructures in the protoplanetary disk.
Page updated
Google Sites
Report abuse