The Andromeda Galaxy is one of the closest large clusters of stars to our home galaxy. It is part of the so-called local group of galaxies, whose members, in addition to it, are our Milky Way with satellite galaxies and the Triangulum galaxy (which may also have satellites, not yet discovered). In fact, the closest to the Milky Way are small clusters - the Large and Small Magellanic Clouds. The galaxy itself combines about a trillion stars (and this is five times more than in our own), and the radius of its circumference is more than 110 thousand light years. The Andromeda Nebula is two and a half million light-years away, and the most advanced spacecraft to date would take 46 billion years to get there. This is at least six times larger than the Earth exists. It's hard to imagine such numbers!
History of observations of the neighboring galaxy
Dense clusters of stars in the sky have been seen since the Middle Ages. In particular, in one of the Arab chronicles NebulaAndromeda is referred to as a small cloud. This cluster of stars, located in the constellation Andromeda (for which, in fact, the nebula got its name) has been observed by astronomers for centuries. However, without significant progress in its description. However, technological possibilities have allowed humanity to take a step forward in this regard. In 1885, an interesting event occurs - a supernova exploded in the Andromeda galaxy, and the attention of astronomers around the world turned to this cluster.
True, according to one version, it exploded a long time ago, several million years ago, and what scientists took for the birth of a new star is just light from the explosion, which only now (or rather, in 1885) reached to the Earth. The Andromeda Nebula, photographed for the first time in 1887, appears to astronomers in the form of a huge spiral cluster of bodies. A stunning discovery was made in 1921 by the American Westo Slifer. Calculating the trajectory of the galaxy, he found out that the Andromeda Nebula is rushing straight towards the Milky Way at a monstrous speed. According to modern estimates of astronomers, in 4 billion years there will be a merger of two galaxies. It will not look like a collision at all, but the stars of the two clusters will most likely undergo a significant regrouping and change in their own orbits. Surely many bodies will even be forced out of the newly formed galaxy into interstellar space. Interestingly, in 1993, in the center of the Andromeda Nebula,another cluster of stars. Perhaps it is a trace of another galaxy, swallowed up by the Nebula millions of years ago.
Features of the Nebula
According to the ideas of modern astrophysicists, there are supermassive black holes at the centers of most spiral galaxies. They are difficult to see due to the large pile of celestial bodies in the centers of the spirals, as well as due to the lack of radiation or reflection of light. However, black holes can be detected by observing how they affect other objects. Curiously, there are two such supermassive black hole candidates at the same time in the core of the Andromeda Nebula.
