All-Sky Automated Survey for SuperNovae receives $1.5 million from Alfred P. Sloan Foundation
The Payne-Gaposchkin telescope at the Las Cumbres Observatory site in South Africa.
The All-Sky Automated Survey for Supernovae (ASAS-SN), an Ohio State-led automated telescope network that observes the entire sky every night, has received a five-year, $1.5 million grant from the Alfred P. Sloan Foundation. The grant will help fund continued ASAS-SN operations through August 2026, guaranteeing its all-encompassing surveys continue providing images and data to support and inform research spanning all branches of astronomy.
“It remains the only project in optical light that actually observes the whole sky frequently,” said ASAS-SN co-principal investigator Kris Stanek, professor and University Distinguished Scholar in the Department of Astronomy. “It’s awesome that foundations like Sloan want to support this research. We are very grateful.”
From left: Kris Stanek, Chris Kochanek, Todd Thompson
ASAS-SN consists of 20 automated telescopes distributed around the world that combine to compile thousands of images per night to find things up to 50,000 times fainter than the human eye can see. The images are catalogued and compared to previous images of the same patches of sky to look for objects that have changed in brightness — in particular, explosive, transient events. These include exploding stars (supernovae), tidal disruption events where a star is ripped apart by a supermassive black hole and events associated with other probes of the variable sky like neutrinos.
ASAS-SN’s surveys have led to a host of significant astrophysical discoveries. In 2015, it discovered the most powerful supernova ever seen — one 20 times brighter than all the stars in the Milky Way galaxy combined. In 2019, ASAS-SN recorded the most detailed tidal disruption event on record. Last January, it discovered a repeating tidal disruption event in which the star orbiting a supermassive black hole has a piece of its mass torn off once every 114 days, the first such object ever found.
An artist's depiction illustrating a repeating tidal distruption event discovered by ASAS-SN in which the star orbiting a supermassive black hole has a piece of its mass ripped away every 114 days.
ASAS-SN’s data is publicly available and is used for research projects by astronomers around the world, with a paper using its data published, on average, every other day. Anyone can determine how an object in the sky bright enough to be observed by ASAS-SN is changing in brightness.
For the researchers at Ohio State, making ASAS-SN’s data free to use is vital and adheres to a precedent already set by the Alfred P. Sloan Foundation.
“There’s a famous survey in astronomy, the Sloan Digital Sky Survey, that from nearly the beginning offered its data publicly,” said Todd Thompson, University Distinguished Scholar, professor and interim chair of the Department of Astronomy. “That had a pretty significant effect on the field, and it’s one of the reasons why Sloan supports us because we make the data public. There’s a history of that with the Sloan Foundation in astronomy.”
“As Yogi Berra once said, ‘You can observe a lot by just watching,’” Stanek said. “We will see an ever-increasing stream of exciting discoveries. We don’t know what will happen next week, but I can promise that something will happen. That’s by virtue of observing the whole sky. If you’re observing 100 million objects, ‘one in a million’ is no longer unusual. That’s the beauty of ASAS-SN.”
The ASAS-SN team at Ohio State consists of co-principal investigator Christopher Kochanek, Ohio Eminent Scholar and professor of astronomy; astronomy graduate students Tharindu Jayasinghe, Patrick Vallely, Dominick Rowan and Jack Neustadt; research assistants Zachary Way and Dhvanil Desai; Center for Cosmology and Astroparticle Physics (CCAPP) fellow Subhash Bose; and Distinguished University Professor in the Department of Physics and CCAPP director John Beacom. ASAS-SN is supported by the Las Cumbres Observatory and funded in part by the Gordon and Betty Moore Foundation, the National Science Foundation, the Mt. Cuba Astronomical Foundation, the Center for Cosmology and AstroParticle Physics at Ohio State, the Chinese Academy of Sciences South American Center for Astronomy and the Villum Fonden in Denmark.
ASAS-SN is funded in part by the Alfred P. Sloan Foundation under grant G202114192. The Alfred P. Sloan Foundation is a philanthropic nonprofit organization that funds research and education in science, technology, engineering, mathematics and economics.