It’s a well-known fact that black holes are everywhere in space, ranging from stellar masses to supermassive ones. They are known for their strong gravitational fields that don't let anything, not even light, escape. In recent decades, scientists have observed the fascinating process of how they devour stars. Now, a new study has discovered 18 black holes gobbling up nearby stars— indicating that this is more common than previously thought.
Researchers from the Massachusetts Institute of Technology (MIT) showed in a recent study 18 new tidal disruption events (TDEs) — extreme instances when a nearby star is tidally drawn into a black hole and ripped to shreds. They noted that when the black hole eats the stars, it gives off a massive burst of energy across the electromagnetic spectrum, a press statement from MIT explained.
Previously, astronomers detected TDEs by keeping an eye on characteristic bursts in the optical and X-ray bands. But searches through this method were limited, revealing about a dozen star-shredding events in the nearby universe.
In the new study, researchers used infrared observations to pick out many more TDEs, even in galaxies where these were previously hidden. The team’s new TDEs are more than double the number of known TDEs in the universe.
“The majority of these sources don’t show up in optical bands,” lead author Megan Masterson said in the statement. “If you want to understand TDEs as a whole and use them to probe supermassive black hole demographics, you need to look in the infrared band.”
For this, they searched through data collected by NEOWISE — the renewed version of Nasa’s Wide-field Infrared Survey Explorer, the statement explains. The researchers developed an algorithm to detect patterns pointing towards TDEs in the infrared spectrum. Their method revealed 18 “clean” signals of TDEs in a range of systems, indicating that they are not occurring only in one type of galaxy, as previously thought based only on optical and X-ray searches.
“It is now possible to peer through the dust and complete the census of nearby TDEs,” Edo Berger, professor of astronomy at Harvard University, who was not involved with the study said in the statement. “A particularly exciting aspect of this work is the potential of follow-up studies with large infrared surveys, and I’m excited to see what discoveries they will yield.”