In space, found a perfect sphere
A group of astrophysicists led by Laurent Gizona (Laurent Gizon) of the max Planck Institute in Germany have discovered the most round object known in the Universe. He was a star KIC 11145123 located about five thousand light-years from Earth. Briefly about the discovery tells Gizmodo.
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It is known that most stars (and planets) are not perfectly spherical, as they are flattened due to rotation around the axis, and the actions of its own poloidal (passing through the poles) magnetic fields. To determine the shape of space objects scientists have typically used optical interferometry, but its low resolution made it possible to study only close to the Solar system a rapidly rotating star.
In the current study turned to astrophysics astroseismology method. Using the data obtained by the Kepler telescope, they measured the frequency of the periodic pulsations of the white star KIC 11145123. Since this parameter depends on the geometry of the space object, scientists were able to determine the degree of its deformation.
It turned out that the Equatorial radius of the star is only three kilometers more than the polar. Such a small compression is not only extremely slow rotation (three times slower than the Sun), but the influence of magnetic fields, which prevent the flattening KIC 11145123.
Considering that the average radius of the star is 1.5 million kilometers, this object can be considered almost a perfect sphere. Other space bodies, for example the Sun, the difference between the Equatorial and polar radii is 10 kilometers, and the Earth is 21 km.
The researchers intend to use astroseismology method for the study of other stars observed by the Kepler telescope. The approach will help to study the peculiarities of their magnetic fields, and rotation speed and other characteristics influence the shape of the space objects.