Podcaster: Richard Drumm
Title: Space Scoop: The Star That Would Not Die
Organization:365 Days Of Astronomy
Link : astrosphere.org ; http://unawe.org/kids/unawe1730/
Description: Space scoop, news for children.
Bio: Richard Drumm is President of the Charlottesville Astronomical Society and President of 3D – Drumm Digital Design, a video production company with clients such as Kodak, Xerox and GlaxoSmithKline Pharmaceuticals. He was an observer with the UVa Parallax Program at McCormick Observatory in 1981 & 1982. He has found that his greatest passion in life is public outreach astronomy and he pursues it at every opportunity.
Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by — no one. We still need sponsors for many days in 2016, so please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at signup@365daysofastronomy.org.
Transcript:
This is the 365 Days of Astronomy Podcast. Today we bring you a new episode in our Space Scoop series. This show is produced in collaboration with Universe Awareness, a program that strives to inspire every child with our wonderful cosmos.
The Star That Would Not Die
Just like all good stories, the life of a star has a beginning, a middle and an end.
The most massive stars end their tales in a most dramatic fashion. They light up the sky in an explosion that’s bright enough to outshine an entire galaxy and violent enough to send the star’s guts flying out into space like so much cosmic flotsam & jetsam.
A supernova!
Supernova iPTF14hls is the supernova under consideration in today’s podcast.
When the dust eventually settles from a supernova, all that remains is the collapsed core of the once mighty star. This will be either a neutron star or a black hole.
Over the years, thousands of supernovae have been seen and studied by astronomers like Iair Arcavi, a NASA Einstein postdoc fellow at Las Cumbres Observatory and UCSB.
So, when Iair spotted a new supernova back in 2014, he thought nothing of it. Like all other supernovae, this one lit up the night sky for a short time, before beginning to fade away.
Just your ordinary, everyday star blowing up!
Since the event looked like it was coming to and end, he moved on to other projects.
A few weeks later,though, he returned to check up on the fading star and was astonished to see that it was getting brighter again.
Unbelievably, the star looked as if it had exploded a second time.
For the next two years, Iair and his team watched in amazement as this star broke all records. Over 600 days, the star brightened and dimmed five times — it was erupting over and over again!
What’s more, delving into the star’s past revealed that it has exploded at least once before, over 60 years ago.
So, what’s happening? Well, the truth is, no-one really knows.
The best guess is that the explosions are not being caused by the star collapsing, like a normal Type II core-collapse supernova.
You see, Supernova iPTF14hls may be the first example of a so-called “Pulsational Pair Instability Supernova.” The theory holds that massive stars become so hot in their cores that energy is converted into matter and antimatter.
This would cause an explosion that blows off the outer layers of the star and leaves the core intact; this process can repeat over decades before the large final explosion and collapse to a black hole.
When the antimatter touched the normal material in the star, it resulted in a powerful explosion. This allowed the star to flare up again and again.
But, like all good stories, the tale of this star has come to an end. After 600 days, the poor, exhausted star could no longer continue its cosmic fireworks display. After one last explosion, it began to fade forever…
We think.
Hey, Here’s A Cool Fact:
The star that exploded was at least 50 times more massive than our Sun — and probably much larger. It may have been the most massive supernova ever seen!
However, the “Pulsational Pair Instability” theory may not fully explain all the data obtained for this event. For example, the energy released by the supernova is more than the theory predicts there should be.
So this supernova may be something completely new.
End of podcast:
365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by Astrosphere New Media. Audio post-production by Richard Drumm. Bandwidth donated by libsyn.com and wizzard media. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. This year we will celebrate more discoveries and stories from the universe. Join us and share your story. Until tomorrow! Goodbye!