Occasionally, they awaken from a relatively quiet state and eat surrounding matter.

Other explanations are plausible but unlikely.

Even now, its luminosity grows.

Most black holes are inactive, making them effectively invisible.

However, the conditions necessary to initiate an AGN remain unclear.

Studying SDSS1335+0728 the first activation observed in real time will allow scientists to learn more about these events.

If the sudden brightness is from a TDE, it would be the slowest ever recorded.

Still, astronomers cannot rule out the possibility entirely since TDEs aren’t well understood.

It could be a particularly exotic event.