The scientists demonstrated that the random stellar motions can be explained only by a 'recent' collision, which was followed by an episode of star formation spread over all the huge Andromeda disk.ħ to 10 billion years ago, instead of Andromeda, there were two galaxies on an encountering orbit. The French-Chinese scientific team of the Paris Observatory - PSL, the National Astronomical Observatory of China (NAOC), the Astronomical Observatory of the University of Strasbourg, and the CNRS finally succeeded in characterizing the physical mechanisms of the Andromeda formation, so lifting the veil on its origin. The study is based on numerical modelling made on the most powerful available computers in France - of the Paris Observatory ( MesoPSL) and GENCI (IDRIS - CNRS)-, with the processing of about one terabyte of data. In comparison, stars of the disk of the Milky Way, e.g., our Sun, are subject only to a simple rotation.

In the huge Andromeda disk, all stars older than 2 billion years undergo random motions, the scale of which being almost comparable to their rotation around the centre of this galaxy. It is our closest neighbour and this allows the observers to scrutinize its properties, which intrigued the astrophysicists until today.Īn observational campaign made between 2006 in 2014 by American astronomers, has underlined a considerable difference with the Milky Way. Listed in 1923 as a galaxy, Andromeda has been often considered as the twin sister of our Milky Way. In 964, the Persian astronomer, Abd al-Rahman al-Sufi described for the first time the large nebula of Andromeda.

Lang - 2018 monthly planner -