By Nadia Drake
Scientists are closer to understanding an enormous two-decade-long eruption that transformed one of the galaxy’s most massive stars into a fireball millions of times brighter than the sun.
From 1838 to 1858, astronomers watched the binary giant star Eta Carinae erupt, shedding more than 10 solar masses of material and producing an oddly shaped, double-lobed cloud 7,500 light years from Earth. Scientists have thought a dense stellar wind fueled Eta Carinae’s outburst, and considered it the prototype for “supernova impostors,” or shorter-lived eruptions that don’t quite destroy a star.
But new observations of Eta Carinae’s Great Eruption suggest an explosion may have been its cause, says study coauthor Armin Rest, an astrophysicist at the Space Telescope Science Institute in Baltimore, Md. While scientists already knew much about the star and its current state, Rest says they were missing information about the outburst itself, originally observed without the aid of modern technology.