New findings were published in the journal Nature Astronomy in April 25, concerning the measurements of a star. Astronomers discovered the size of the smallest star measured to date by recording the shadows of close asteroids. Even by the best telescope, the majority of the stars in the night sky are way too far to be measured with precision, however, astronomers took advantage of a method known as diffraction to clear this issue.
Diffraction shows up when an object, for example an asteroid, sweeps in front of a star, birthing a shadow known as occultation. As the object passes in front of the star, the size of the star can be calculated by measuring how long it takes for the star’s light to diminish. Knowing how fast an asteroid is moving, researchers can regulate the size of the star. According to a statement from the Harvard-Smithsonian Center for Astrophysics (which manages the observatory utilized in the study), astronomers were able to measure more accurately the diameter of various distant stars by using this method.
Using the Very Energetic Radiation Imaging Telescope Array System (VERITAS) at the Fred Lawrence Whipple Observatory in Amado, Arizona, astronomers tracked the asteroid Imprinetta which is 60 kilometers wide (37 miles) as it passed in front of the star named TYC 5517-227-1, on Feb. 22, 2018.
There were taken about 300 images per second to precisely measure the diffraction pattern in the asteroid’s shadow.
The data then unveiled that the diameter of the star, located 1,674 light years from Earth, is 11 times bigger than that of Earth’ Sun. According to the declaration, the star is now labeled as a red giant as is much greater than it was formerly thought.
This technique was repeated when the 88-kilometer wide (55 miles) asteroid Penelope crossed in front of the star TYC 278-748-1 on May 22, 2018, a sun-like star, located 700 light years from Earth. This heavenly body is the smallest star so far measured.