Magellanic clouds

The closest galaxies to us that leave the dwarf category are the Large and Small Magellanic Clouds. The first is located at a distance of about 160 thousand light years from us, the second - 200 thousand. The clouds are gravitationally connected to each other, the distance between them is about 75 thousand light years. Each of the Clouds makes up several percent of the mass of our Galaxy, which, given the large size of the latter, is by no means small - billions of stars.

In reference books, Magellanic clouds are classified as irregular galaxies. However, scientists find evidence that these are deformed spirals with a bridge: in particular, traces of spiral arms are visible. In both galaxies, a much larger proportion of the mass than in ours is gas. Both contain significantly less heavy elements than our Galaxy. It’s as if they were underevolved in comparison with the Galaxy, which is quite natural due to their small mass.

However, now the Magellanic clouds are catching up: they are undergoing such a rapid process of star formation that some of its manifestations are unique to the entire Local Group of galaxies. Thus, in the Large Magellanic Cloud there is the most active and powerful star-forming region in the Local Group - the Tarantula Nebula near the star 30 Doradus (NGC 2070). The second image (from the Spitzer Space Telescope) shows its general appearance in infrared light. In the center of the nebula is the brightest cluster of young stars in the Local Group, R 136 (third image, Hubble). If we moved the Tarantula to the site of our Orion Nebula, the complex would cast a shadow at night, like the Moon. There are complexes of comparable grandeur in the Small Magellanic Cloud: the fifth image (Hubble) shows one of them, NGC 346. The closest supernova in the last four centuries (1987) exploded in the Large Magellanic Cloud. There are also many relatively fresh supernova remnants, for example LMC N49, which is shown in the fourth image (Hubble).

The reason for intense star formation in the Magellanic clouds is gravitational interaction with our Galaxy. Thanks to the turbulent phase of their lives, the Magellanic Clouds have become an excellent laboratory for modern astronomy, where many phenomena and interesting objects can be observed in a single field of view of a telescope, such as hundreds of massive young stars shining thousands of times brighter than the Sun.

Prepared the strip
Boris Stern