Webb Researchers Discover Lensed Supernova, Confirm Hubble Tension
Editor’s Note: This post highlights data from Webb science in progress, which has not yet been through the peer-review process.
Measuring the Hubble constant, the rate at which the universe is expanding, is an active area of research among astronomers around the world who analyze data from both ground- and space- based observatories. NASA’s James Webb Space Telescope has already contributed to this ongoing discussion. Earlier this year, astronomers used Webb data containing Cepheid variables and Type Ia supernovae, reliable distance markers to measure the universe’s expansion rate, to confirm NASA’s Hubble Space Telescope’s previous measurements.
Now, researchers are using an independent method of measurement to further improve the precision of the Hubble constant — gravitationally lensed supernovae. Brenda Frye from the University of Arizona, and a team of many researchers from different institutions around the world, are leading this effort after Webb’s discovery of three points of light in the direction of a distant and densely populated cluster of galaxies. We invite Dr. Frye to tell us more about what the team has nicknamed Supernova H0pe and how gravitational lensing effects are providing insights into the Hubble constant:
“It all started with one question by the team: ‘What are those three dots that weren’t there before? Could that be a supernova?’ The points of light, not visible in 2015 Hubble imaging of the same cluster, were obvious when the images of PLCK G165.7+67.0 arrived on Earth from Webb’s Guaranteed Time Observations of the Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS) ‘Clusters’ program. The team notes the question was the first to pop to mind for good reason: ‘The field of G165 was selected for this program due to its high rate of star formation of more than 300 solar masses per year, an attribute that correlates with higher supernova rates.’
