Astronomers Observe the Bright Flash from a Star’s Explosion for the First Time
For the first time ever, astronomers have captured the bright flash of a shockwave blasting out from a dying star, NASA reported. The brilliant sight, known as a “shock breakout,” was seen by NASA’s Kepler probe — a space telescope designed to search for planets outside the Solar System. Kepler was able to observe the visible light from the shockwave, which was about 130,000,000 times brighter than the Sun.
“The shock breakout was about 130,000,000 times brighter than the Sun”
To see this explosion, Kepler measured the light coming from 500 galaxies over a three-year period. Astrophysicists at the University of Notre Dame then analyzed this data in 30 minute increments, looking for indications of massive star explosions or supernovae. They found that Kepler recorded the explosions of two giant stars in 2011 — one that was 300 times the size of our Sun and one that was about 500 times the Sun’s size. However, Kepler was only able to observe the shock breakout from the bigger star, possibly because the smaller one was obscured by too much nearby gas.
Kepler’s measurements of the supernova event. After the initial explosion, the star continues to grow and will become up to 1 billion times brighter than the Sun. (NASA)
There’s no recording of the event, but NASA made a great animation to illustrate what Kepler saw. The beginning of the video shows the star, called a red supergiant, just before its nuclear fusion core collapses. That collapse creates a shockwave that races from the center of the star up to the stellar surface. At first, the shockwave breaks through the surface in the form of plasma jets, but about 20 minutes later, it blasts the entire star apart in an enormous flash. The video also shows Kepler’s measurements of the event in real time with the animation.
NASA is interested in studying these kinds of supernovae, since star explosions are thought to be responsible for many of the complex chemicals we see throughout the cosmos. The idea is that when stellar objects explode, they spread heavy elements out in every direction through the Universe. These elements then wind up in other stars or planets. “All the silver, nickel, and copper in the Earth and even in our bodies came from the explosive death throes of stars,” said Steve Howell, project scientist for NASA’s Kepler mission. “Life exists because of supernovae.”