Astronomers have made a groundbreaking observation, witnessing the sudden reawakening of a supermassive black hole in the galaxy SDSS1335+0728.

Located approximately 300 million light-years away in the constellation Virgo, this galaxy had been relatively inactive for two decades.

Let's dive into the background and discovery of this fascinating event.

In December 2019, the Zwicky Transient Facility telescope detected a dramatic brightening in the galaxy, prompting further investigation.

This led to a multi-year observational campaign from 2019 to 2024, utilizing various telescopes and instruments.

What did the astronomers find during their observations?

The study, published in Astronomy & Astrophysics, reveals a consistent increase in emission across ultraviolet, optical, infrared, and X-rays.

This behavior is unprecedented, as typical events such as supernovae or tidal disruption events usually last only a few dozen to a few hundred days.

What could be causing this unusual phenomenon?

The most plausible explanation is that the supermassive black hole is becoming active, feeding on a rich source of gas and dust.

"Imagine you've been observing a distant galaxy for years, and it always seemed calm and inactive. Suddenly, its core starts showing dramatic changes in brightness, unlike any typical events we've seen before." Paula Sánchez Sáez, 2024.

Why is this observation significant?

This observation provides valuable insights into how black holes grow and evolve, raising the possibility of witnessing a similar event in our own galaxy.

What comes next for astronomers studying this phenomenon?

Follow-up observations are planned using advanced instruments like the Very Large Telescope's Multi Unit Spectroscopic Explorer (MUSE) and the Extremely Large Telescope.

"Regardless of the nature of the variations, [this galaxy] provides valuable information on how black holes grow and evolve." Paula Sánchez Sáez, 2024.

Let's take a look at the timeline of this discovery.

December 2019: Initial brightening detected. July 2021: UV emission found to be around four times brighter. 2022: Infrared emission doubles. February 2024: Galaxy starts emitting X-rays. June 2024: Study published.

Here are some key statistics about this observation.

Distance to SDSS1335+0728: Approximately 300 million light-years. Mass of the supermassive black hole: Around one million solar masses. Duration of observed emission: Over four years.