AstroTalk Episode April 26, 2018

Intro to Wormholes. A Stellar Thief, or Survivor to a Supernova Explosion.

2:01pm - 2:59pm

Intro to Wormholes. A supernova, 2001ig, in galaxy NGC 7424, 40 million light years away, has been spotted with a surviving companion star. This proves that some supernovas originate in double-star systems. The majority of massive stars are in binary pairs, and many of these binary pairs will interact and transfer gas from one star to the other when their orbits bring them close together. The companion siphoned off almost all of the hydrogen from the doomed star’s stellar envelope, the region that transports energy from the star’s core to its atmosphere. Millions of years before the primary star went supernova, the companion’s thievery created an instability in the primary star, causing it to episodically blow off a cocoon and shells of hydrogen gas before the catastrophe. How stripped-envelope supernovas lose that outer envelope is not entirely clear. They were originally thought to come from single stars with very fast winds that pushed off the outer envelopes. The problem was that when astronomers started looking for the primary stars from which supernovas were spawned, they couldn’t find them for many stripped-envelope supernovas. Now they have. Astronomers hope to use the James Webb Space Telescope in the future to study this pair in more detail. A brief discussion of multi-star systems. Details are published in the March 2018 issue of Astrophysical Journal. Thanks for visiting Giorgio.