Astronomers have found the most circular star object in the observable universe.

Stars do not possess the forms of an ideal sphere. The reason for this is centrifugal force. However, about 5,000 light-years from our home, scientists have found, as they call it, the most circular natural object ever measured in the observable universe.

On the pages of one of the latest issues of Science Advances, scientists describe the star Kepler 11145123 - the most spherically symmetrical object in the universe. To find and measure a star, a team led by Laurent Gizon of the Max Planck Institute for Solar System Research helped the team determine the periodic expansion and contraction of the star. By comparing the data, scientists were able to describe a spherical object with unprecedented accuracy.

When the stars rotate, they are subject to centrifugal force, which flattens them slightly. The faster the star spins, the more oblate it becomes at the poles and more convex in the equatorial region. Since the Kepler 11145123 star spins very slowly (about three times slower than our Sun, which takes 27 days to complete a full turn), the result is that it is experiencing very low gravitational pressure. Using data collected with the Kepler space telescope, the Ghison team determined that the difference in radius between the equatorial zone and the pole zone is only about three kilometers.

Of course, it is impossible to call this star an ideal sphere, but it stands out very strongly against the background of other stars. For example, the radius in the equatorial region of our Sun is 10 kilometers larger than at the poles. The Earth, which looks more like a pumpkin, the difference is even more noticeable, since it is already 21 kilometers. Scientists also note that the Kepler 11145123 star is twice the size of our Sun, which makes the difference in radii even more noticeable.

The Guizon team has already selected and compiled a list of potentially interesting stars, possibly with an almost perfect spherical shape. They are planning to study and measure them using the same technique that was used in the case of Kepler 11145123. It will be interesting to know for how long this star will keep the palm among the most circular objects in the Universe.

The article is based on materials https://hi-news.ru/research-development/astronomy-nashli-samyj-kruglyj-zvezdnyj-obekt-v-nablyudaemoj-vselennoj.html.