ESA said that Z 229-15 is a galaxy, which is a gravitationally bound collection of stars.
National Aeronautics and Space Administration's (NASA's) Hubble Space Telescope captured a series of photos of a celestial object, Z 229-15 that lies about 390 million light-years from Earth. The celestial object lies in the constellation Lyra.
Z 229-15 first appears to be a spiral galaxy, thanks to its two spiralling arms of stars emanating from a bright core. According to a statement released by European Space Agency (ESA), 229-15 is one of those interesting celestial objects that fits several classifications. "Z 229-15 is one of those interesting celestial objects that, should you choose to research it, you will find defined as several different things; sometimes as an active galactic nucleus (an AGN); sometimes as a quasar; and sometimes as a Seyfert galaxy" the statement reads.
It further says that the mysterious object can be all of those things at once due to an overlap in the definition of those terms.
ESA shared that Z 229-15 is indeed a galaxy, which is a gravitationally bound collection of stars. It is an active galactic nucleus (AGN) that is far brighter than just a galaxy's stars would be. "The extra luminosity is due to the presence of a supermassive black hole at the galaxy's core. Material sucked into a black hole actually doesn't fall directly into it, but instead is drawn into a swirling disc, from where it is inexorably tugged towards the black hole. This disc of matter gets so hot that it releases a large amount of energy across the electromagnetic spectrum, and that's what makes AGNs appear so bright," ESA said.
Z 229-15 is also a quasar- a particular type of AGN. They are typically both extremely bright and extremely distant from Earth - several hundred million light-years are considered nearby for a quasar, making Z 229-15 positively local. Often an AGN is so bright that the rest of the galaxy cannot be seen, but Seyfert galaxies are active galaxies that host very bright AGNs (quasars) while the rest of the galaxy is still observable. So, Z 229-15 is a Seyfert galaxy that contains a quasar, and that, by definition, hosts an AGN. Classification in astronomy can be a challenge!