Hubble captures a mysterious object that challenges its classification

March 31 () –

The NASA/ESA Hubble Space Telescope has captured a celestial object 390 million light years from Earth in the constellation of Lyra, which defies its classification.

When investigating Z 229-15, it sometimes shows up as an active galactic nucleus (an AGN); sometimes like a quasar; and sometimes as a Seyfert galaxy. Which of these is really the Z 229-15? The answer is that it is all of these things at once, because these three definitions have significant overlap, reports NASA.

An AGN is a small region at the heart of certain galaxies (called active galaxies) that is much brighter than the stars in the galaxy would be. The extra luminosity is due to the presence of a supermassive black hole at the core of the galaxy. Material sucked into a black hole doesn’t actually fall directly into it, Instead, it is drawn into a rotating disk, from where it is inexorably drawn into the black hole. This disk of matter gets so hot that it releases a huge amount of energy across the electromagnetic spectrum, and that’s what makes AGNs appear so bright.

Quasars are a particular type of AGN; in general, they are extremely bright and extremely distant from Earth: several hundred million light-years are considered close for a quasar, which makes 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 containing a quasar, and by definition hosting an AGN.