How do stars die, explode, and release heavy elements into the universe? These questions are the subject of an international team of scientists led by the University of Hawaii Institute of Astronomy (If a) Postdoctoral Research Fellow Chris Ashall. Researchers recently received two programs to conduct detailed observations with NASA’s $ 10 billion James Webb Space Telescope (JWST), the flagship mission, scheduled to launch in the fall of 2021.
Exploding stars, called supernovae, produce most of the heavy elements, such as iron, calcium, and silicon, in the universe. These elements form the building blocks of life. Supernovae may also be major producers of cosmic dust, but the exact nature of these explosions remains a mystery.
“We may finally be able to understand the final stages of a star’s life, how they explode, what heavy elements they make, and how those elements are redistributed throughout the universe,” Ashall said. “It is truly an extremely exciting time for supernova science.”
JWST will have the ability to observe objects at longer wavelengths than its predecessor, the Hubble Space Telescope. Observations at these redder wavelengths, in the mid-infrared, can detect signatures of elements that were not previously visible.
Ashall and the MIR SuperNovA collaboration (MIRSNAC) will obtain spectra with JWST at medium infrared wavelengths about 7 to 40 times redder than what the naked eye can see. Ashall and MIRSNAC will observe two different types of supernovae – those resulting from the death of single and massive stars, called Type II, and those resulting from the explosion of stars of lower mass commonly called white dwarfs, called Type Ia.
Type observations II Supernovae will help determine how much cosmic dust these massive hydrogen-rich stars produce when they die. Type Ia observations will identify masses of white dwarf stars when they explode. This data can be used to measure distances to galaxies and has been vital in determining that the expansion of the universe is accelerating.
Ashall and the MIRSNAC are among the few groups selected to have accepted two projects in the first round of JWST observations. If a will be the center of the collaboration, which consists of more than 30 international scientists from numerous institutes, including Aarhus University, European Southern Observatory, Florida State University, University of California, Davis, University of Oklahoma and the Carnegie Observatories.
If a astronomers will also perform detailed tracking observations of galaxies seen in the images of JWST. The project is part of the COSMOS-Webb program, made up of nearly 50 researchers from 30 institutions around the world, including If a, which will use the Maunakea telescopes to help NASA generate a three-dimensional map of the universe.
This research is an example of EUH Mānoa’s research excellence goal: to advance the business of research and creative work (PDF), one of the four objectives identified in the 2015–25 strategic plan (PDF), updated in December 2020.