Researchers have discovered the largest yellow star measuring 1300 times more than the diameter of sun. The star dubbed HR 5171 A, was discovered nearly 12000 light-years from Earth in the constellation Centaurus is the largest member of the family of yellow stars of which our sun belongs. The new image of the star was released on 12 March 2014.
The star was studied by a team lead by Oliver Chesneau of the Cote d'Azur Observatory in Nice, France with the Very Large Telescope in Atacama, Chile. In their study they found that the yellow hyper giant star is much bigger than it was expected.
The researchers claimed that it is one of the ten largest stars found and is about 50 percent larger than red supergiant Betelgeuse. The star is about one million times brighter than the Sun. Yellow hypergiants are very rare and only about a dozen of such stars are known in our galaxy of which the most famous known is Rho Cassiopeiae.
These stars are among the biggest and brightest known stars and are at an unstable stage of their lives and are changing rapidly. This instability allows them to expel material outwards by forming a large extended atmosphere around themselves.
The team has also discovered a companion star of HR 5171 A that orbits it every 1300 days. The smaller companion is only slightly hotter than the surface temperature of 5000 degrees Celsius of HR 5171 A.
Astronomers to combine the light collected from multiple individual telescopes have made a technique named interferometry that helps in effectively creating a giant telescope up to 140 meters in size.