More than 70 years ago, Albert Einstein claimed that theoretically, it was possible to measure the mass of a star. However, he said that we will never reach the point when we could actually do that. According to some recent developments, it turns out that he was both right and wrong. Astrophysicists have recently managed to measure the mass of a white dwarf star for the first time ever, with the help of gravitational microlensing.
But Why Is It Important?
It is quite important for us to know the mass of a star. Based on that, we are able to find more about its birth, death, composition, and size. Will it turn into a supernova? What evolution will it have? The mass can answer these questions and much more.
A team of scientists that work at the Space Telescope Institute in Baltimore has taken advantage of the Hubble Space Telescope and used it to calculate the mass of the star Stein 2051B. They managed to do so by detecting the way in which light bent around it. Just like Einstein, the team of scientists knew that the light that comes from a distant star bends when it hits a massive object. The bend is small indeed (namely 0.0000005555555556 degrees, which is ~ 2 milliarcseconds), but if they could measure that, they could find out the mass of a white dwarf star.
Proving Einstein Wrong
As such, the team managed to prove Einstein wrong, by actually succeeding in measuring the mass of a star. However, he was also right in giving the right importance to the mass of a star. As it turns out, the Stein 2015B star has a mass that accounts for 68% of our sun. The next goal for the scientists is to find out the mass of a huge array of stars.