Sedna, the dimmest of the known large object of the Solar System, has no companion. This fact has surprised many astronomers — it was thought that its slow rotation caused by the action of gravity lower body of the satellite. Now that this hypothesis is refuted, the researchers believe that it is unexpectedly discovered fact can tell a lot about the origin and evolution of objects on the edge of the solar system.
On the discovery of Sedna, it was reported on March 15, but then began arguing, can we consider this body of the tenth planet. Co-author of the new discoveries — Mike Brown of the California Institute of Technology — was so convinced of the coming of satellites that even commissioned artist intended image of the surface of Sedna, which the satellite was drawn.
After the announcement of the discovery of Sedna, astronomers decided to examine it with the "Hubble", characterized by an incredibly sharp vision (this telescope can see the soccer ball at a distance of a thousand miles). Photo taken by "Hubble", showed a lone Sedna and very dim and distant star in the same field. In such circumstances, the satellite would have to be seen.
The picture has given astronomers more thing — let find out that the diameter of Sedna is approximately three-quarters the diameter of Pluto — about 1,600 kilometers.
What is it, remains unknown. There is a possibility that the calculation of the orbital period of Sedna. But a group of Brown rejects this option. According to available information, astronomers now have, period of Sedna is more than 20 days. While almost all of the small solid objects in the solar system, such as asteroids and comets make appeal on its axis in a few hours.