Astronomers have discovered what they thought was a supernova in the galaxy ESO 253-G003. The All Sky Automated Survey for Supernovae (ASAS-SN) captured what appeared to be a supernova November14, 2014. Years after its initial discovery, astronomers again detected the supernova in the same place and took a look at the data again. They discovered that the presumed supernova actually occurs every 114 days! This event was obviously something very different.

Astronomers predicted when an outburst would occur and mounted a coordinated observation. They discovered, after several observations, that the host galaxy contains two supermassive black holes. One of the black holes has a star orbiting it and its orbit is not circular.

During the orbit, each time the star gets close enough to the black hole, it strips matter from the star. The material from the star then orbits the black hole with some of it flung into space and the rest consumed by the black hole. The process repeats each time the star gets close to the black hole and it currently happens about every 114 days.

This process where the black hole consumes some of the orbiting star each time it gets too close to the black hole is called a tidal disruption event, or TDE. Rather than consuming the star entirely, each orbit only consumes some of the star. As a result, it is not known exactly how long these regular outbursts will occur because astronomers don’t know the orbiting star’s initial mass. It is estimated that the equivalent mass of three Jupiters gets consumed at each TDE.

The last TDE happened on December 26, 2020.

You can observe the host galaxy and possibly the TDE using the telescopes at or

The host galaxy is called ESO 253-G003 and its coordinates are Ra: 05:23:52.762 and Dec: -46:02:55.72. You need to use a telescope located in the southern hemisphere to observe this galaxy.

Here is a link to the Simbad page for galaxy ESO 253-G003.

Here is a link to the paper at arXiv which discusses the discovery.