The Roundest Object in Nature is a Star 5,000 Light-Years Away
With the help of the Kepler telescope, the closest thing to a perfect sphere has been discovered some 5,000 light-years away from Earth. As many people know, stars, planets, and heavenly bodies develop a slight bulge at their equators due to the centrifugal force, which itself is a result of its spin around its axis. The faster the spin, the bigger the bulge.
To give you an example, our Sun rotates around its axis every 27 days, and thus its equator is bigger than the diameter from pole to pole by 12 miles, or 20 kilometres. In comparison, the equatorial diameter of Earth is 26 miles (42 km) longer than its polar diameter. And even though the Earth is much smaller than the sun, due to the fact that the Earth spins on its axis every 24 hours, has led it to the big discrepancy.
This distant star, Kepler 11145123, is so far the roundest object that has been measured so far in nature. However, there is a sphere made by man which sits in a lab, somewhere, which is by far the roundest object ever, but this star here formed naturally.
NASA, with the use of the Kepler space telescope, observed the star for a period of 51 months, from 2009 until 2013, and observe that Kepler 11145123 had an equatorial diameter, longer than its pole one, by a mere 3.7 miles (6 kilometres). This is a star with a diameter of 1.86 million miles in diameter (3 million km.) – twice the size of our sun.
The Kepler Telescope is used to detect exoplanets by looking for the tiniest of light fluctuations coming from stars when a planet travels in front of it. With this technology, the team, led by Laurent Gizon from the Max Planck Institute for Solar System Research and the University of Göttingen in Germany, then used this information to determine the star’s size. With it, scientists can also determine what various stars are made out of, similar to how geologists determine the inside of our planet via earthquakes.
“This makes Kepler 11145123 the roundest natural object ever measured, even more round than the sun,” Gizon said in a statement.
The reason this star, in particular, is so round is because it rotates around its axis three times slower than the sun. Its magnetic field might also play a role here since this one too can have an effect on the symmetry of the star. The team, however, say that Kepler 11145123 might not keep this shape forever, and might change over time.
“It will be particularly interesting to see how faster rotation and a stronger magnetic field can change a star’s shape,” Gizon said. “An important theoretical field in astrophysics has now become observational.”
The new study was published in the journal Science Advances.