Free Astronomy Magazine September-October 2024

20 SEPTEMBER-OCTOBER 2024 ASTRO PUBLISHING brightness, unlike any typical events we’ve seen before.” This is what happened to SDSS1335+0728, which is now classified as having an ‘active galactic nucleus’ (AGN) — a bright compact region powered by a mas- sive black hole — after it brightened dramatically in December 2019. Some phenomena, like supernova explosions or tidal disruption events — when a star gets too close to a black hole and is torn apart — can make galaxies suddenly light up. But these brightness variations typ- ically last only a few dozen or, at most, a few hundreds of days. SDSS1335+0728 is still growing brighter today, more than four years Astronomers see a massive black hole awaken in real time “I magine you’ve been ob- serving a distant galaxy for years, and it always seemed calm and inactive,” says Paula Sánchez Sáez, an astronomer at ESO in Germany and lead author of the study published in Astronomy & Astrophysics . “Suddenly, its [core] starts showing dramatic changes in by ESO − Bárbara Ferreira