In December 2019, astronomers using the Zwicky Transient Facility on California’s Palomar Mountain detected an extraordinary flare of light from a distant galaxy in the Virgo constellation, approximately 300 million light-years away. This flare, identified in the galaxy SDSS J1335+0728, has persisted with notable fluctuations over the past four years, a duration far longer than typical cosmic events.
Paula Sánchez-Sáez of the European Southern Observatory and her team suggest that the flare is caused by a massive dormant black hole at the galaxy’s center awakening and consuming surrounding gas. This gas heats up intensely before falling into the black hole, producing the observed light.
If confirmed, this event would be the first direct observation of a black hole transitioning from a dormant state to an active phase. The black hole in question is significantly larger than the Sun and had been dormant for at least two decades before the flare began in 2019.
Lorena Hernández GarcÃa from the Millennium Institute of Astrophysics in Chile, a co-author of the study, emphasized that this prolonged and intense flare is unprecedented for this type of galaxy. Data from multiple telescopes indicate that SDSS J1335+0728 is now emitting much more light across various wavelengths, including ultraviolet, optical, and infrared.
The sustained four-year flare suggests an unusual event, possibly involving the black hole shredding a star that ventured too close. Typically, stellar disruptions by black holes last only a few hundred days. This extended flaring is distinct from supernovas, which are explosive events resulting from stars depleting their fuel and usually last for days to months.
The mystery behind the prolonged glow continues to intrigue astronomers as they investigate the processes governing black hole behavior and its impact on galaxy evolution over cosmic timescales.
