Astronomers at the University of Arizona recently completed a mathematical model of the star VY Canis Majoris, a red supergiant that is currently the largest known star in our galaxy, the Milky Way Galaxy. This model, based on the results of real astronomical observations, will allow scientists to predict what will happen at the very end of the star’s life cycle.
Scientists have long argued about the “death” processes of red supergiant stars. Previously, astronomers believed that the final stage is a fairly trivial supernova explosion. However, recent observational data shows a discrepancy between the number of observed supernova explosions and the number of explosions, taking into account the explosions of red supergiants. And, according to the new theory, such stars collapse into black holes, which is much harder to track, confirm and study.
The star VY Canis Majoris is an excellent object to study. It is quite large, its size is 10 to 15 AU (astronomical units, the distance between the Sun and the Earth). And it is located only 3,009 light-years away in the region of the constellation Canis Majoris.
Such relative proximity and the size of the star VY Canis Majoris allow astronomers not only to see the star itself, but also to monitor the processes taking place on its surface. Huge formations have been observed there, which are similar to the arcs of the solar corona, but billions of times larger. These arcs and other processes are responsible for the star’s loss of mass, one of the fundamental processes of completing its life cycle.
The matter expelled from the surface of the star VY Canis Majoris, and more specifically its radio emission, has been studied with the ALMA radio telescope. In addition to the traditional hydrogen, helium, oxygen and carbon, sulfur dioxide, silicon dioxide and even sodium chloride (table salt) were found there. This variety of substances allowed scientists to see matter streams and determine their velocity with fairly high accuracy.
To make the observations, the scientists aligned and oriented all 48 antennas of the ALMA telescope in the right direction. And the volume of data collected exceeded one terabyte. The processing of the entire dataset is not yet complete, but the results already obtained are enough to create a mathematical model of the star VY Canis Majoris.
When all the data processing is finished, the model will be adjusted accordingly, and scientists will be able to find out what exactly the biggest star in our galaxy looks like. And sometime in the very distant future, scientists who witness the final moments in the life of the star VY Canis Majoris will be able to test the validity of this model.
