Visually, it appears as a faint, fuzzy "star" with a slightly elliptical glow – the quasar point source embedded in a dim galaxy.
The nearest quasar is a topic of significant interest in astrophysics, as quasars are among the brightest and most distant objects in the universe. A quasar (Quasi-Stellar Radio Source) is an incredibly luminous object thought to be a distant galaxy with a supermassive black hole at its center. This black hole is actively accreting material, which heats up and releases enormous amounts of energy across the electromagnetic spectrum, making quasars visible from vast distances.
The nearest known quasar to Earth is ULAS J1342+0928, which is about 1.34 billion light-years away. This quasar is significant not only for its proximity but also for the insights it provides into the early universe. The light we see from ULAS J1342+0928 today has been traveling through space for about 1.34 billion years, giving us a glimpse of what the universe looked like in the distant past.
Located approximately in the constellation Ursa Major, Markarian 231 (Mrk 231) is officially recognized as the nearest galaxy to Earth hosting a quasar.
Intriguingly, some observations suggest Mrk 231 may contain orbiting each other. The secondary black hole would be about 150 times the mass of our Sun – small for a supermassive black hole but huge for a stellar-mass one. If confirmed, it would be the closest known binary supermassive black hole system.