Supermassive black hole gobbled up a star in the 1980s, and high schoolers helped discover it
According to new research, astronomers discovered signs of a black hole snacking on a star in data collected in the 1980s.
The researchers claim to have found the signal of such an event in 1980s data thanks to a pair of high school interns from Massachusetts. When a star gets too close to a black hole, the massive object’s gravity pulls on it, pulling matter into the black hole and causing a flare of light in what astronomers call a tidal disruption event. While astronomers have observed this phenomenon approximately 100 times, relatively few of those sightings rely on radio data, as the event of the 1980s does.
“Gravity around the black hole will shred these unlucky stars, causing them to be squeezed into thin streams and fall into the black hole,” Vikram Ravi, an astronomer at the California Institute of Technology (Caltech) in Pasadena, said in a statement. “This is a really messy process. The stars don’t go quietly!”
In historical observations flagged by interns Ginevra Zaccagnini and Jackson Codd, Ravi and his colleagues discovered the signature of a tidal disruption event. The teenagers were reviewing data from the National Radio Astronomy Observatory’s (NRAO) Karl G. Jansky Very Large Array (VLA) in New Mexico when they discovered that a particularly powerful signal seen in the mid-1990s had decreased by 2017.
The team began exploring for more observations of the object, named J1533+2727, and discovered that the similar object had been observed by the Green Bank Observatory’s 300-foot (90-meter) radio telescope before its untimely collapse in 1988. In fact, Green Bank measurements from 1986 and 1987 indicated the object to be significantly brighter than the researchers’ first 1990s data. Overall, the researchers said, the object is now 500 times dimmer than it was at its brightest.
The blinding flare was most likely created by a supermassive black hole 500 million light-years away from Earth, which destroyed a star and spat out a radio jet, according to the scientists’ study of the event.
The researchers expect that these and similar events will help them better understand tidal disruption events (TDEs), the black holes that generate them, and the galaxies in which these black holes live.
“Interestingly, neither of the radio-discovered candidates were found in the type of galaxy most popular for TDEs,” Hannah Dykaar, a PhD student in the department of astronomy and astrophysics at the University of Toronto and a co-author on the new research, said in the same statement. “Finding more of these radio TDEs could help us to illuminate ongoing mysteries about what types of galaxies they occur in and just how many there are in the universe.”
The researchers have also turned to another program, the Zwicky Transient Facility (ZTF) at Caltech’s Palomar Observatory, in the goal of detecting more tidal disruption events that produce radio wave explosions.
“This is the first discovery of a relativistic TDE candidate in the relatively nearby universe, showing that these radio-bright TDEs may be more common than we thought before,” Ravi said.
The findings were presented on Monday (Jan. 10) in conjunction with the American Astronomical Society’s 239th meeting, which was canceled due to COVID-19. The research work has been approved for publication in The Astrophysical Journal and is now available on the pre-print service arXiv.org.