Galaxies come in all shapes and sizes, but in general they can be divided into easily identifiable or regular ones, such as spiral or mediocre elliptical. And then there are irregular galaxies, which account for about a quarter of known galaxies and which are just curiously dirty.
In a recent observation of the Hubble Space Telescope, one of these irregular galaxies was discovered, located about 16 million light years from Earth. It looks like a loose collection of stars, thrown together, and then scattered, as I did in my end of a semester at the university, in a room in a dormitory. But this galaxy, called NGC 5408, is not just a scattering of stars! This is a whole galaxy, which has a certain history.
It was originally discovered by the British astronomer and mathematician John Herschel in June 1834. Initially, NGC 5408 was supposedly a planetary nebula — a gas cloud of gas generated by a dying star. But over time, as astronomical optics improved, its true nature was revealed; NGC 5408 is still a galaxy living by its own rules, which refuses to conform to the correct form. According to a NASA press release, NGC 5408 is distinguished by its ultra-bright X-ray source, known as NGC 5408 X-1. This class of object can belong to the intermediate mass of a black hole, one of the most popular astrophysical objects in space.
Intermediate masses of black holes (or IMBHs from English) are the "average weight" of a black hole, which are believed to have gone missing in an evolutionary connection between the stellar mass and giant black holes. They are very difficult to find, and astronomers are currently monitoring ultra-bright X-ray sources in the hope that they can catch some kind of signal.
