This star has a mass just large enough to support nuclear fusion of hydrogen, the process required to power stars<\/a>, and so represents a lower bound on star size.<\/p> Named EBLM J0555-57Ab and located 600 lightyears<\/a> away, it is part of a binary star system<\/a> and was detected when it passed in front of its much bigger companion, in what is called an eclipsing stellar binary system.<\/p> \u201cOur discovery reveals how small stars<\/a> can be,\u201d said Alexander von Boetticher at the University of Cambridge<\/a>, lead author of the study that announced the discovery of EBLM J0555-57Ab, the smallest known star, on 12 July 2017.<\/p> \u201cHad this star formed with only a slightly lower mass, the fusion reaction of hydrogen in its core could not be sustained, and the star would instead have transformed into a brown dwarf.\u201d<\/p> EBLM was identified by the Wide Angle Search for Planets<\/a> (WASP), a collaboration aiming to find exoplanets<\/a>, using the transit method<\/a>.<\/p> Astronomers noticed that its parent star became dimmer in a periodic manner.<\/p> This signifies an orbiting object, normally a planet, is passing in front of it, and the mass and size of the companion can be accurately measured from observation data.<\/p> \u201cThis star is smaller, and likely colder, than many of the gas giant exoplanets that have so far been identified,\u201d says von Boetticher.<\/p> \u201cWhile a fascinating feature of stellar physics, it is often harder to measure the size of such dim low-mass stars than for many of the larger planets.<\/p> “Thankfully, we can find these small stars with planet-hunting equipment, when they orbit a larger host star in a binary system.<\/p> “It might sound incredible, but finding a star can at times be harder than finding a planet.\u201d<\/p> Scientists believe these very small, dim stars are the best candidates for finding Earth-sized planets with liquid-water on their surface because of examples like TRAPPIST-1, an ultra-cool dwarf surrounded by seven temperate Earth-sized worlds.<\/p>![\"A](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2019\/04\/small-star-sizecomparison-main-65bca76.jpg\")
How the smallest known star was found<\/strong><\/h2>
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