image: Thousands upon thousands of stars illuminate this breathtaking image of star cluster Liller 1, imaged with Hubble’s Wide Field Camera 3. This stellar system, located 30,000 light-years from Earth, formed stars over 11 billion years.
Credit: ESA/Hubble & NASA, F. Ferraro
As part of its commitment to unraveling the universe’s mysteries through sustained support of the astrophysics community, the Flatiron Institute is securing the future of MESA (Modules for Experiments in Stellar Astrophysics), an open-source software suite that has transformed how researchers model the evolution of stars.
As MESA’s creator, Bill Paxton, steps down, the Flatiron Institute’s Center for Computational Astrophysics (CCA) is stepping up to support MESA’s need for ongoing maintenance and continued development. CCA has hired Philip Mocz as a full-time software engineer to help ensure MESA’s bright future for the collective benefit of the astrophysics community.
“MESA has revolutionized astronomy and keeps on growing, meaning it needs maintenance and expansion,” says Mocz. “Open source means open science, and it is exciting to be a part of this effort.”
Matteo Cantiello, a research scientist at CCA, says, “There is an intention and attention to supporting open-source software at CCA and the Flatiron Institute. As Bill was reducing his involvement with MESA, the project was also facing challenges in maintaining its funding, so CCA jumped in to provide stability and support for this key software.”
With Mocz’s appointment, the center of gravity for the MESA project moves to CCA, marking a new chapter for the software suite. Since its beginnings in 2011, the code has been adopted globally by more than 1,000 astrophysicists, the publications describing its capabilities have been cited more than 12,000 times and it has been employed and adapted for stellar investigations that have resulted in thousands of scientific publications.
This success is in large part due to researchers from around the world who have contributed code to the project since its early days. The MESA developers team, a core group of volunteers who build and maintain the code, has been instrumental in sustaining the project throughout its history — from conception to Paxton’s retirement and beyond — and fostering a community of users and developers through workshops, events and training.
“I never imagined MESA would have so many users and such a large scientific impact,” says Paxton. “The CCA’s collaborative work with the MESA developers and the community will ensure it continues to make significant contributions to stellar physics.”
Tools such as MESA are critical for analyzing the deluge of observational data collected by telescopes and satellites, says Cantiello. “New space telescopes and gravitational wave observations have revealed properties of stars that hadn’t been predicted,” he says. “Most of the big discoveries in the last decade have had a theoretical component that involved MESA.”
Paxton, a retired computer scientist, introduced MESA to the world as a tool for modeling how stars evolve over their lifespans. Light from stars provides a wealth of information that astronomers and astrophysicists use to study the universe. From their initial formation out of clouds of cosmic gas and dust to maturation when they can sustain nuclear fusion until their death, stars are dynamic and fundamental entities for understanding astrophysical environments.
Advances in observations have generated new data about the lives — and deaths — of stars, but computational modeling is needed to turn those observations into astronomical insights about the underlying physics. MESA provides a state-of-the-art, one-dimensional method for understanding the complex physics involved in a star’s evolution.
“Modern stellar physics requires both precise 1D evolutionary calculations and high-resolution 3D dynamical simulations,” says Cantiello. “With Mocz on board, the CCA is uniquely suited to exploit this zoom-in, zoom-out approach to seamlessly bridge dimensions by integrating MESA with multidimensional tools.”