NASA's Hubble Space Telescope captured an image of the remnant of a binary star system that shows it survived from an explosion. The supernova occurred 17 years ago but only now that scientists were able to see what happened in the aftermath.
This is the first image of a companion star surviving a supernova.
Surviving Star In Binary Star System
About 17 years ago, the supernova called 2001ig occurred in the galaxy NGC 7424, which is 40 million light-years away from earth. Scientists observed it since 2002 and believe that their findings offer proof that some supernovas come from binary star systems. In a statement by NASA, Stuart Ryder from the Australian Astronomical Observatory says that massive stars are usually found in binary star systems
Ryder adds that these pairs will transfer gas between each other when their orbits reach a close point. The surviving star is a player in the supernova happening, it drained most of the hydrogen from its companion star's stellar envelope — a region where energy is transported from a star's core to the atmosphere.
Millions of years prior to the said supernova, the siphoning of the hydrogen from the star caused it to strip a cocoon and shell hydrogen gas.
Supernova In The System
Researchers named this supernova SN 2001ig. It is categorized as a Type IIb stripped-envelope supernova. They believe that this explosion is strange because prior to it happening, most of the hydrogen had been stripped from the star.
Scientists first observed this type of supernova in 1987, it was identified by Alex Filippenko of the University of California, Berkeley. They found that the number of stripped envelope supernovas is greater than expected. For the study, they concluded that half of the stripped envelope supernovas occur in binary star systems, the other half happens when they lose their external envelopes due to stellar winds.
Before this study, scientists believed that stripped envelope supernovas occurred only when the single star had the external envelope blown off by stellar winds. This created a problem when researchers began to look for single stars they weren't able to find them. Scientists believed that these stars would be the biggest and brightest stars.
They came to the conclusion that primary stars were in lower-mass binary star systems. It proved difficult to be able to find a binary system after a supernova explosion. This system would have to be close in distance to Earth for the Hubble Space Telescope to be able to see it and they would have to know the exact coordinate because of how faint it is.
Scientists knew the location of SN 2001g because it was mapped using the Very Large Telescope in Chile in 2002. They were able to see the star after the supernova's glow faded and the star became visible.