Kepler Captures Supernova Shockwave in Visible Light

Mining of Kepler space mission data reveals “supernova’s shockwave” in visible light


Space news (massive supernovae) – 1.2 billion light-years from Earth –

An international team of scientists at the University of Notre Dame in Indiana mining three years of Kepler Space Telescope data for massive supernovae discovered something never seen during the human journey to the beginning of space and time. Buried in the Kepler data Peter Garnavich and team observed for the first time the brilliant flash of a massive supernova’s shockwave in visible light as it reached the surface of the exploding star.

NASA scientists Peter Garnavich. Credit: NASA

“In order to see something that happens on timescales of minutes, like a shock breakout, you want to have a camera continuously monitoring the sky,” said Garnavich. “You don’t know when a supernova is going to go off, and Kepler’s vigilance allowed us to be a witness as the explosion began.”

Garnavich’s the leader of the Kepler Extragalactic Survey (KEGS) research team, which is currently mining NASA’s Kepler K2 mission data looking for massive supernovae. NASA’s repurposed planet hunter is expected to detect around a dozen more events during its mission to capture the light from hundreds of distant galaxies and trillions of stars.

The diagram illustrates the brightness of a supernova event relative to the sun as it unfolds. For the first time, a supernova shockwave has been observed in the optical wavelength or visible light as it reaches the surface of the star. This early flash of light is called a shock breakout. 

Astronomers call the brilliant flash of a supernova’s shockwave “a shock breakout”. This event only lasts around twenty minutes in the cases observed, so catching the flash as it happens is truly a milestone for astronomers studying supernovae. By piecing together individual moments of a supernova astronomers hope to learn more about the history of chemical complexity and the evolution of life.

“All heavy elements in the universe come from supernova explosions. For example, 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 and K2 missions at NASA’s Ames Research Center in California’s Silicon Valley. “Life exists because of supernovae.”

NASA scientist Steve Howell. Credit: NASA

Massive supernovae and their less energetic brothers are the seeds of chemical complexity in the cosmos, spreading the elements of creation across the breadth of the universe. Understanding the physics behind these titanic events can help tell us how these elements of creation were spread across the universe.

Kepler observes two massive supernovae

The Kepler Space Telescope observed a type II supernova shockwave in visible light as it broke the surface of the star for the first time in history as supermassive red giant KSN 2011d went supernova in 2011. Containing roughly 500 times the mass of Sol, this supermassive star at the moment the shockwave from the supernova reached its surface was 130,000,000 times brighter than the Sun. Continuing to explode and grow, the star eventually reached a maximum brightness over 1 billion times greater than Sol 14 days later.

This artist’s conception of the repurposed Kepler K2 spacecraft. Credit. NASA/Kepler K2

The Kepler Space Telescope also observed a second type II supernova in 2011. Red super massive star KSN 2011a contains 300 times as much mass as Sol and occupies a volume of space that would easily engulf the orbit of Earth around the Sun. Only 700 million light-years from Earth, astronomers weren’t able to observe a shock breakout in the data for this supernova, but they think it might be due to gas masking the shockwave as it reached the surface of the star.

“That is the puzzle of these results,” said Garnavich. “You look at two supernovae and see two different things. That’s maximum diversity.”

“While Kepler cracked the door open on observing the development of these spectacular events, K2 will push it wide open observing dozens more supernovae,” said Tom Barclay, senior research scientist and director of the Kepler and K2 guest observer office at Ames. “These results are a tantalizing preamble to what’s to come from K2!”

Drawing of Tom Barclay. Credit: Tom

Watch this YouTube video on this event here.

Learn more about K2.

Discover what the Kepler Extragalactic Survey has told us here.

Take the voyage of the Kepler Space Telescope.

Learn more about type II supernovas here.

Discover NASA.

Learn more about astronomy at the University of Notre Dame here.

Read about the giant bubble observed by the Hubble Space Telescope.

Learn more about the prominent emission lines in young stars.

Read about two merging black holes astronomers are watching.