[photo credit: The Huntington Library, Art Museum, and Botanical Gardens]
“When an unsuspecting star wanders too close to a supermassive black hole, the star can be ripped apart by the black hole’s immense gravity,” explains Piro. “As the black hole messily feeds on the star, it produces an amazing display of light as bright as ten billion suns for many months.”
The lecture will focus on tidal disruption events (TDEs), rare cosmic phenomena first theorized in the late 20th century and observed more frequently since the advent of deep-sky surveys. These events occur when stars are torn apart by black holes, creating electromagnetic flares visible across the universe that can last several months. Piro will discuss recent discoveries made possible by advanced astronomical surveys like the Zwicky Transient Facility and Pan-STARRS.
A key highlight of the presentation will be the mysterious “heartbeat” phenomenon observed years after these feeding events. Scientists have discovered that some black holes produce periodic X-ray eruptions that repeat every several hours long after consuming a star. In 2024, MIT scientists identified 18 new TDEs, more than doubling the number of known events in the nearby universe.
Piro will present current theories explaining these unusual X-ray patterns, with leading models suggesting disk instabilities or delayed accretion processes as possible causes. These findings stem from ongoing research documented in peer-reviewed publications including the Astrophysical Journal Letters.
The event underscores Pasadena’s prominent role in astronomical research and its historical leadership in astrophysics. Carnegie Science Observatories, one of the oldest independent astronomical research institutions in the U.S. established in 1902, joins other local institutions like Caltech and National Aeronautics and Space Administration’s Jet Propulsion Laboratory in advancing our understanding of the universe.
Black holes themselves are detected through indirect methods, as explained in the source materials. Astronomers observe the gravitational effects on nearby objects, detect X-rays from hot gas in accretion disks, and measure gravitational waves from black hole mergers to infer their presence and properties.
As a theoretical astrophysicist, Piro specializes in compact objects like black holes and neutron stars. His research combines expertise in thermodynamics, radiative transfer, nuclear physics, and fluid dynamics to predict and understand novel astrophysical phenomena.
The lecture will be held at The Huntington Library, Art Museum, and Botanical Gardens, located at 1151 Oxford Road in San Marino. While admission is free, attendees must make reservations in advance through the Huntington’s website. This public science lecture provides the community with access to cutting-edge astrophysical research and enhances public understanding of cosmic phenomena.
For more information or to reserve a seat, visit www.huntington.org/
