About

Earl Bellinger is an Assistant Professor in the Department of Astronomy at Yale University, with a secondary appointment in the Foundations of Data Science Institute. He leads the Yale AstroML (YAML) research group, which focuses on utilizing big data and artificial intelligence to address various problems in astronomy and astrophysics. His research primarily aims to advance understanding of the structure and formation of the Milky Way and its satellite galaxies through the study of pulsating stars. Additionally, he employs stellar pulsation data to explore issues related to stellar evolution, fundamental physics, and beyond-standard-model physics.

Research topics

• Computer Science
• Physics
• Astrophysics
• Optics
• Computational physics
• Nuclear engineering
• Mechanics

Selected publications

• Modules for Experiments in Stellar Astrophysics (MESA): Time-dependent Convection, Energy Conservation, Automatic Differentiation, and Infrastructure

  The Astrophysical Journal Supplement Series · 2023 · 517 citations

  • Computer Science
  • Physics
  • Astrophysics

  Abstract We update the capabilities of the open-knowledge software instrument Modules for Experiments in Stellar Astrophysics ( MESA ). The new auto _ diff module implements automatic differentiation in MESA , an enabling capability that alleviates the need for hard-coded analytic expressions or finite-difference approximations. We significantly enhance the treatment of the growth and decay of convection in MESA with a new model for time-dependent convection, which is particularly important during late-stage nuclear burning in massive stars and electron-degenerate ignition events. We strengthen MESA ’s implementation of the equation of state, and we quantify continued improvements to energy accounting and solver accuracy through a discussion of different energy equation features and enhancements. To improve the modeling of stars in MESA , we describe key updates to the treatment of stellar atmospheres, molecular opacities, Compton opacities, conductive opacities, element diffusion coefficients, and nuclear reaction rates. We introduce treatments of starspots, an important consideration for low-mass stars, and modifications for superadiabatic convection in radiation-dominated regions. We describe new approaches for increasing the efficiency of calculating monochromatic opacities and radiative levitation, and for increasing the efficiency of evolving the late stages of massive stars with a new operator-split nuclear burning mode. We close by discussing major updates to MESA ’s software infrastructure that enhance source code development and community engagement.

  DOI

• The Aarhus red giants challenge

  Astronomy and Astrophysics · 2020 · 52 citations

  • Physics
  • Astrophysics

  Context. With the advent of space-based asteroseismology, determining accurate properties of red-giant stars using their observed oscillations has become the focus of many investigations due to their implications in a variety of fields in astrophysics. Stellar models are fundamental in predicting quantities such as stellar age, and their reliability critically depends on the numerical implementation of the physics at play in this evolutionary phase. Aims. We introduce the Aarhus red giants challenge, a series of detailed comparisons between widely used stellar evolution and oscillation codes that aim to establish the minimum level of uncertainties in properties of red giants arising solely from numerical implementations. We present the first set of results focusing on stellar evolution tracks and structures in the red-giant-branch (RGB) phase. Methods. Using nine state-of-the-art stellar evolution codes, we defined a set of input physics and physical constants for our calculations and calibrated the convective efficiency to a specific point on the main sequence. We produced evolutionary tracks and stellar structure models at a fixed radius along the red-giant branch for masses of 1.0 M ⊙ , 1.5 M ⊙ , 2.0 M ⊙ , and 2.5 M ⊙ , and compared the predicted stellar properties. Results. Once models have been calibrated on the main sequence, we find a residual spread in the predicted effective temperatures across all codes of ∼20 K at solar radius and ∼30–40 K in the RGB regardless of the considered stellar mass. The predicted ages show variations of 2–5% (increasing with stellar mass), which we attribute to differences in the numerical implementation of energy generation. The luminosity of the RGB-bump shows a spread of about 10% for the considered codes, which translates into magnitude differences of ∼0.1 mag in the optical V -band. We also compare the predicted [C/N] abundance ratio and find a spread of 0.1 dex or more for all considered masses. Conclusions. Our comparisons show that differences at the level of a few percent still remain in evolutionary calculations of red giants branch stars despite the use of the same input physics. These are mostly due to differences in the energy generation routines and interpolation across opacities, and they call for further investigation on these matters in the context of using properties of red giants as benchmarks for astrophysical studies.

  DOI

Frequent coauthors

• S. Hekker

  111 shared

• Y. Lebreton

  73 shared

• R. M. Ouazzani

  63 shared

• George C. Angelou

  Max Planck Institute for Astrophysics

  57 shared

• Sarbani Basu

  51 shared

• Warrick H. Ball

  University of Birmingham

  46 shared

• S. E. de Mink

  35 shared

• Dennis Stello

  UNSW Sydney

  34 shared

Education

• Ph.D.

  Max Planck Institute for Solar System Research

  2018

• M.Sc. Computer Science, School of Informatics and Computing

  Indiana University

  2014

• B.Sc. Computer Science, B.Sc. Applied Mathematics

  SUNY Oswego

  2012

Awards & honors

• Hoffleit Scholarship
• Dorrit Hoffleit Scholars
• Yale F&ES Graduate Student Award
• Brouwer Prize Recipients
• Yale Time Allocation Committee

Similar researchers at Yale University

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• Liangbing Huh-172
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• Alan Kazdinh-142
• Douglas L. Rothmanh-125