StarTalk Radio - Super-Duper Novas with Michael Shara
Episode Date: July 1, 2025When will the last supernova be? Neil deGrasse Tyson and Chuck Nice explore types of novas, freaky binary star systems, core collapse, standard candles, and the explosive future of Betelgeuse with ast...rophysicist Michael Shara.NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free here: https://startalkmedia.com/show/super-duper-novas-with-michael-shara/Thanks to our Patrons Devon Gromko, Ron C, Blake Flynn, michelle slaughter, Mia Ham, Ryan Jacobs, Philipp Fallon, Ashley Sandfort, Sam, John Munn, Fred Rubin, TJ Kochhar, Zeraka, Jason Huddleston, Richard Ireland Jr, Judy, Darren Lawson, Bob, Rahul Phatak, Santiago Salas Ventura, Nicholas Bartlett, John D Sostrom, Byron E, Jeremy Corbello, Josh Kirkman, Daniel Carneiro, Tommyboi711, Thomas Hall, Keith Rogers, Luke Hargrett, Darren, Tassos Souris, Patrick GRindol, Erin Anthony, Duane Wolfe, PcuriousJ, Greg Gredvig, Trey Nicholson, Torsten Diekhoff, Sergiu Neacsu, Scott Woodman, FredDawg, Corey He, Kolja Milankovic, Jim Ransom, Kris Waygood, Suvi Irvine, Sarath, Cody Knotts, Jose Trejo, Lauren, Maverick91, Gloss, James, AComatoseLemur, and Ivan Dsouza for supporting us this week. Subscribe to SiriusXM Podcasts+ to listen to new episodes of StarTalk Radio ad-free and a whole week early.Start a free trial now on Apple Podcasts or by visiting siriusxm.com/podcastsplus.
Transcript
Discussion (0)
Chuck, it's great to have colleagues who are the world's expert on something, just arms
reach down the hallway.
Yeah, I would not know what that is like.
In this case, stars that blow up.
Cool.
That is so cool.
Coming up on Star Talk.
Welcome to Star Talk, your place in the universe where science and pop culture collide.
StarTalk begins right now.
This is StarTalk. Neil deGrasse Tyson, your personal astrophysicist. We're going to do cosmic queries today. Chuck.
Hey, Neil.
Did you collect the cosmic query?
I did. And they're not just random this time.
No, they are not.
They were solicited on the topic of stars that blow up.
Oh, and by that we mean those nasty stars that are just mean to all the other stars.
Oh, is that how that works?
Yeah.
I haven't checked the sociology of the galaxy lately.
There's a friend and long time friend and colleague of mine
who works right down the hall,
who is one of the world's experts on stars that blow up.
Dr. Professor Curator Michael Schara, Mike.
Good afternoon.
Welcome back to Star Talk.
It's a real pleasure to be here again.
Do you guys realize he was our first hire when we rebuilt the Rose Center?
Really?
So 25 years ago, the Rose Center's been here 25 years, but we built the Department of Astrophysics
to prepend that.
We got Michael and we said, and now we can build around Michael.
And you came from the Hubble Space Telescope Institute.
I did. So you came from the Hubble Space Telescope Institute. I did.
So you and Hubble go way back.
I was there more than 40 years ago,
and I was in fact the first scientific hireer
without tenure, who got tenure
at the Space Telescope Institute.
So you were there.
Pre-launch.
That's the origin story of the Hubble Institute.
I was hired there seven and a half, almost eight years before the launch of the telescope.
Wow.
That's like being on Krypton before
Nile was launched.
So that's on the campus of Johns Hopkins
University.
Correct.
In Baltimore.
That is right.
Right.
Right.
3,700 San Martin Drive.
Whoa, there it is.
And we were delighted that you were ready for
a change and you came to join us here.
It's been 26 fabulous years.
The only condition of my hire was that I not blow
up like the stars I study.
I'm still here, still having more fun.
Plus he wanted some opera tickets, I think.
You know, I think that was in the deal that we cut with him.
Okay.
That works.
So Mike, tell us about stars that blow up.
First, first disentangle the fact that the word
Nova and supernova looks like one is just a sort of a,
uh, an extra version of the other, but they're two
completely different things in the universe. They are completely different things, but
there's not just novus or novi and supernovas.
There are micronovas, there are dwarf novus.
There are recurrent novus, novus, supernovas,
sub supernovas and hypernovas.
And they're all.
You sound like you're just making shit up right now.
I was going to say once you get past supernova, you know.
Well, if you find something that is more energetic and brighter, right.
Lasts longer and even more unexpected than a supernova.
You got to give it a title.
Cause you're already titled super to supernova.
Because at the time you titled that, that was super.
That was the ultimate.
And now we know there are things that are a lot brighter and even more,
in a sense, explosive than supernova.
So had I been around at the search for that new term, I would have called it super duper
nova.
Way more fun.
And when some of me and my explosive star friends are sitting around over a beer, that's
what we refer to them as.
Super duper nova.
Super duper nova.
So let's back up.
So the stars, nova literally from Latin means new.
Right.
Yet it's the star at the end of its life or at the end of its long live the life before
it goes nova.
So it's really misnamed.
Long before it goes super nova, there's a real difference because novas.
Let's start with novas.
Let's, okay, let's do in a sense the simpler thing.
Novas are stars that explode, but don't die.
Gotcha.
Every Nova explodes, not just once or twice, but
thousands of times.
Oh, it's a Christian Bale star.
These are things that explode over and over again.
And there can be years between the explosions of Novas.
These are called recurrent Novas or centuries, millennia,
even a million years, because something has to be rebuilt.
The explosive part has to be rebuilt
and then it explodes again.
Because the star is still there.
The star, the underlying star,
and it turns out that every Nova is a binary star.
So the stars, plural, are still there after the explosion.
Did you say every Nova is a binary system?
That's correct.
So is, does that mean that one star is feeding another star?
That's exactly right.
And feeding may not be exactly the right word.
You might think of it as a kind of cannibalism
involuntary feeding.
Oh my.
Of one star by the other.
Wait, wait.
And it's worse.
Wait, wait, wait.
But the big bulbous star that's handing over
the matter, it was asking for it because it
was, it's, it's, it's, it's in, in, it's actually in its space.
It's in its space.
It's up in the space.
Up in the space.
And the little star is like, why are you on my grill, man?
That's exactly correct.
I'll give you that.
It's also worth remembering that there's a kind of zombification going on here.
Ooh.
Cause the little star is almost always what we call a compact degenerate object,
either a white dwarf or a neutron star or a black hole.
Hi-ho.
Listen, I got a gambler problem.
What can I say?
So it's not just, you have some overbearing bulbous, hasn't been able to
control itself star involved, but it's
actually being eaten by this nearby, very
compact.
Very compact.
So in Nova it's January.
It actually takes two to tango.
Very much so.
Right.
Okay.
Tell me exactly what's happening.
So the secondary star, is that what it's called?
The big one.
The mat, it's sometimes called the donor,
sometimes called the secondary star.
That star also has to be in a late stage of its
own life to become a red giant and swell to become
so large to overspill the gravity boundary.
That happens in some cases, but it doesn't
actually have to be a red giant.
It can be a main sequence star, still
burning hydrogen.
Just like the sun.
Just like the sun.
Our sun, yeah.
Identical to the sun in every way.
And the reason that it's starting to be
accreted onto or it's feeding the companion
is just that it's so close.
Right.
That as a little bit of it expands, just a
tiny bit of expansion during its evolution,
the nearby star has enough gravity to be able
to immediately vacuum off, suck off any
material that expands beyond a certain radius.
So it doesn't have to be.
So close orbiting ones, it doesn't have to.
Okay.
Gotcha.
Wow.
So have we, have we ever taken a look at these
systems and seen like planetary, uh, systems
around them?
We've looked, it would be an extremely
unpleasant environment for any planetary system.
Nobody has found one. Okay.
Even if it was there, it would be extremely
hard to find cause there's a lot of light being
given off by these guys.
They're intrinsically.
Gotcha.
They have hotspots.
See, I see.
The accretion disc, the donut of material around
the compact star is quite bright.
It flickers like crazy.
And any planet would be of course, thousands
of times or hundreds of times less massive
than the two stars.
Well, just when you say the disc flickers, is
that every time a little bit of matter hits it,
you get a little bit of bright spot.
You have stuff being sucked off the donor into a
doughnut shaped accretion disc, as it's
called around the compact object.
And as that stream of material bangs into the
donut, it causes flickering continuously on a
time scale from minutes to seconds, probably
down to milliseconds.
And the donut is a mechanism to feed the
compact object.
That's.
Okay.
So now why doesn't it just explode as soon as
stuff hits the surface?
You need to not just get a little bit of
hydrogen onto the surface.
Cause if you put a bit of hydrogen on the
surface of a white dwarf, it can just sit there.
The hydrogen doesn't feel the need to explode
until it reaches a certain density and
temperature.
And that critical density and temperature mean
that in the case of a, let's talk about a white
dwarf star, just for concreteness, that's what
most novus are, white dwarf stars.
These are guys that are about the mass of the
sun.
So several hundred thousand times the mass of
the earth, but they're only the size of the
earth.
And how much hydrogen do they need to accrete in order to become explosive?
Well, because they're the size of the earth, about 8,000 miles across, they need to accrete
about a mile of hydrogen, so about a Pacific Ocean's worth of hydrogen onto their surface. At that point, the density and pressure at the bottom of the Pacific
ocean of hydrogen is about 10,000 grams per CC.
So about a thousand times denser than lead.
Temperature reaches 40, 50 million degrees.
At that point, the hydrogen becomes highly explosive.
Nice.
You blow up and you get to be about a hundred thousand to a million times as bright as the sun for a few weeks.
But I need to clarify something.
Yep.
Hydrogen as a gas, right, is explosive.
So that's not what you meant.
Right.
Okay.
So be precise there.
It is not the kind of explosion that you're thinking of in the earth's atmosphere where hydrogen combines chemically with oxygen.
All the humanity.
The last bar for going dark there, guys.
Sorry.
That's it.
The last original ever filled with hydrogen.
We're talking something a hundred thousand or
a million times more energetic because we're
talking nuclear reactions.
Right.
So instead of the hydrogen combining with
oxygen, we're talking about protons smashing
into each other, overcoming the, the, um, the
charge barrier between them, fusing together
basically a hydrogen bomb.
Ah, yeah.
And once you do that, once you become a million times as bright as the sun, you're going to be Charge barrier between them, fusing together, basically a hydrogen bomb.
Ah, yeah.
And once you do that, once you become a million
times as bright as the sun, we can see you not
throughout the Milky way, not just throughout
the Milky way, not just in the Andromeda galaxy,
but I've tracked more than a hundred Novas in
the Virgo cluster of galaxies, 50 million
light years away.
Wow. So these become really, really bright objects. the Virgo cluster of galaxies, 50 million light years away.
So these become really, really bright objects.
So I love the idea that I've never heard of put before when you say the Pacific Ocean
amount of hydrogen because it's also pressure, right, that you need, right?
That's exactly right.
Yeah. So it's like the same way as you get to the bottom of the Pacific, you, you would be
crushed because of the pressure.
It's that same pressure that is causing this
ignition.
And the pressure of course, is causing the
density to be higher and higher.
The higher and higher density pushes the
protons closer and closer together.
Which ordinarily don't want to get together
because they have the same charge.
Science is amazing. I'm sorry. It's just so damn cool. It's just so cool, man.
Let's put a pin in that and now let's go to supernova and then we'll go to our Q&A.
It used to be thought that there were two kinds of supernovas.
Let me guess, type one and type two. That's precisely right.
And of course it turns out that the type one supernovas are in what we call population two. That's precisely right. Two types. And of course it turns out that the type one
supernovas are in what we call population two
galaxies and the type two supernovas just the
opposite.
One of my early books, there was a chapter
titled the confused person's guide to astronomical
jargon.
Nice.
That was the name of the chapter.
That should be like required reading, I think.
Yeah, exactly.
Yeah.
So now with almost a century's worth of study of these things, we know that in very, very first,
very first principles, the broadest way of looking at these supernovas are that they're either
what we call core collapse supernovae.
Okay.
That is massive stars where the inner part of
the star, which holds itself out against the
gravity of the rest of the star loses that pressure.
Somehow that inner part of the star collapses
in on itself.
Okay.
And when it does so, the whole star implodes,
bounces on the inner part of the star.
And then much of the star is blown away.
So that's a core collapse supernova and the
other kinds are what are called.
Single or double degenerate supernovae.
And these are guys stars that are mostly white
dwarfs
that have also lost their source of pressure in their centers, collapse down
to become probably neutron stars in most cases, releasing enough energy to blow off the outer envelope.
And these two very different kinds of supernovas have very different properties in terms of what we see in
their spectra, what we see in the ejecta, the
stuff that's good, that gets blown off of the
two stars.
So we know that they're two very different
things.
And within the core collapse supernovae, they
can be anywhere from, oh, 20,, 40, up to a hundred times the
mass of the sun.
Okay.
While the other ones, the degenerate supernovas
are somewhere between about 1.4 and about three
times the mass of the sun.
So much lower masses.
And those are the ones that also don't pay
child support.
Never.
Yeah.
But they are the ones that let us discover the dark energy.
So as I'm hearing you describe this, I can't help, but recall to mine like
neutron stars, because that's basically what you described if I'm right, a neutron
star, and then if it's spinning very fast, it's
then a pulsar, right?
If it's spinning very fast and has a magnetic field.
Oh, okay.
That's an extremely important part of it, which it
almost certainly does.
And?
And?
The magnetic field can't be aligned with the axis of rotation.
Not perfectly.
It's got to be tipped.
You get all of those things.
You're going to end up with a pulsar for a while.
For a while. For a while.
Maybe a hundred million years.
Listen, that's just a blink.
That's a blink in the eye.
To an astronomer.
Wow, look at that.
After some time, after that hundred million years or so, it's going to go radio quiet.
It's not going to be as interesting.
So for every pulsar we see wandering around out there, there are probably a hundred quiet,
or listen to, so we can hear the beep, beep, beep, there are probably a hundred quiet, or listen
to, that we can hear the beep beep beep, there's probably a hundred quiet ones.
So now here's my last question, because I know I don't want to take up time from the
people.
Are you about to ask a question?
Yes.
Where's your Patreon?
Oh, come on now.
I'm asking on behalf of, let's see. Hahahaha! I'm Nicholas Costella and I'm a proud supporter of Star Talk on Patreon. This is Star Talk with Neil deGrasse Tyson.
Everything you just said seems to me like the same things in the process of creating a black hole, except you need a lot
more mass, and then what happens in the end is that we can't see into it because at some
point the gravity is so great that light can't escape. If that is the case, and this process
is the same, just bear with me, Why can't we study this to kind of know
what's happening inside of a black hole?
The answer is a few parted.
Okay.
So first of all, we only know for sure of one
kind of all the core collapse supernovas,
because there are different kinds of flavors.
Okay.
So think of them as ice cream, there's chocolate,
vanilla, strawberry, raspberry, etc.
Terry Garcia.
So there's many, many, many different subtypes
of the massive star supernovas.
We know of the ones that are called the type two
plateau supernovae,
that they have red super giant progenitors.
That is the stars that make these kinds of supernovas
and almost certainly end up as black holes,
as modest mass black holes are red super giants.
But do you get a supernova with the black hole or not?
Or does everything just get sucked in?
Some of the stuff gets blown off.
Okay.
We think yet, and the reason we think that
is we've seen lots of supernovas and we look
at them, we've observed lots of supernovas.
And when you look really, really carefully,
a century later, two centuries, a thousand
years later, we see a supernova
remnant. We see a big expand, expanding clouded
gas, the crab nebula is maybe the classic
example.
Can you also measure the rate at which the gas
is moving away?
We can.
And turn the clock back and say it must have
started.
1054 for sure. Absolutely.
Hmm.
Right. So that's how we know we're beyond the
shadow of a doubt. And we know that there is a very, very bright,
rapidly spinning neutron star in the
center of that supernova.
There is a beautiful pulsar there too.
So there we have absolute proof, as much as
you can prove anything ever in astrophysics,
that you had an intermediate mass star, maybe
10 or 15 or 20 solar masses that
collapsed down to give you a spinning neutron
star and the supernova remnant.
But there may be dark supernovas too.
There's a good case to be made for some stars,
very, very bright luminous stars that just go
and disappear out of the universe.
I've seen a video of that.
That's pretty cool.
I mean, an animation of it.
Yeah.
It's, it's, it's scary actually.
It's like the whole thing gets flushed
down its own toilet and then there's no,
you know.
Like a snake eating itself.
Yeah.
Yeah.
If you will accept that it's not gone.
Right.
The black hole is still there.
Right.
And if you are a highly adventurous astronaut
racing through the universe and you don't have
the right sensors, you're going to go right down
it, right down the throat of that snake that
swallowed itself and you're not even going to
know it, it's just going to take you right down.
Which of these is responsible primarily for
the heavy elements in the universe?
Probably a combination of them.
Combination, okay.
So one kind of Nova that we didn't mention
before are kilonovas. And the reason that they're called kilonovas universe. Probably a combination of them. Combination. Okay. So one kind of Nova that we didn't mention
before are kilonovas.
And the reason that they're called
kilonovas is because they're about a thousand
times more energetic than a Nova, which is
about a million times the brightness of the sun.
So these are about a billion times the brightness
of the sun and a supernova, which is about a
thousand times brighter than a kilonova.
So you could call it a mega nova, except
we call it a supernova.
And then there are things that are 10 to
a hundred times brighter than that.
And those are the hypernovas and there's
different mechanisms, different things that
are going on in each case.
So, so, but you have that inventory so we can, we can account for the elements in each case. So, but you have that inventory, so we can,
we can account for the elements in the universe.
Yes.
And we have a fear idea just by taking
spectra, breaking up the light into all its
components and measuring what's coming off in
supernova remnants, how much iron, how much
silicon, how much nickel is being produced in
different kinds of supernovas.
So certainly some of the core collapse
supernovas are producing certain kinds of elements.
Probably the collapse of the degenerate objects
is producing much of the iron in the universe.
And ordinary novus are probably producing a good
fraction of the nitrogen in the universe.
So every time you take a breath, you're
breathing in some of the excreta.
Every breath you take.
Every breath you take is some of the excreta of a Nova.
Well, when you say it like that, it's not so pleasant.
I wasn't about to say, thanks, Supernova, but now
I'm like, mmm.
So what you got here?
All right, here we go.
Let's jump into it.
Uh, this is from Dipp I'm like, mm. So what you got here? All right, here we go. Let's jump into it.
Uh, this is from Dippin.
Hello, Dr.
Tice and Dr.
Schauer, your Lordship.
Uh, first we're taught that matter and neutron
stars is strange.
Then we say that collision of neutron stars
creates heavy metals like gold and platinum.
How are these normal metals created
from strange matter?
Great question.
The answer is that while the matter inside a
neutron star is at not just strange, but insane
sorts of densities, one with 13 or 14 zeros
after it grams per cubic centimeters.
So quadrillions, uh, trillions or quadrillions
of grams per cubic centimeter.
Once the kilonova has exploded, maybe some of
it fallen into a black hole, but some of it's
been blown off that expanding matter starts going
down in density.
And so the free neutrons inside the neutron star start combining with each other.
Some of them start decaying into protons, neutrons and protons combined to make nuclei.
And that's how you get ordinary matter. Cause you get out of the
incredibly dense state inside the neutron star. You've escaped, you're free to become yourself.
You're free to become Golderplatt.
That's right, dad.
Oh, that's very cool, man. Great question. All right, this is Stacy Hughes. Hello all, this is Stacy
Hughes from Nebraska. I have heard somewhere that large stars are going to stop being born
before other stars. If that is true, how much sooner than the last stars dying out
will the last supernova be? And what types of stars will be born after the last supernova?
And will we still be here when that happens?
Let me take that last part for you.
Don't look like it.
So, go ahead.
Given the rate at which humans have been developing technologies capable of destroying all of
us, I'm not sure.
I'd say we have maybe a 50 50 chance.
Okay.
Okay.
But if we make it through the next
century or two, maybe we'll get smart enough
or maybe we'll, we'll disperse away from the
earth and be able to hang in there.
Let me answer your question about the
most massive stars.
When we look out in the Milky way galaxy, we
see large clouds of gas and dust.
Okay.
Including things we call giant molecular clouds.
And these are the objects that give birth to
new stars and we see the same kinds of objects
in nearby galaxies and we can image them in
great detail with the Hubble space telescope
or the James Webb space telescope.
And we see clusters of thousands of stars being born now throughout the Milky Way, throughout
nearby galaxies.
And there are almost always some really, really luminous, very, very massive stars in these
youngest clusters up to about a hundred times the mass of the sun.
Will this eventually stop?
Well, we see galaxies where this has stopped
because when galaxies crash into each other
and merge, most of the gas, the hydrogen gas,
the stuff out of which stars is born, much of
it is liberated.
It's blown out of those galaxies.
We're left behind with an elliptical galaxy
that doesn't make many stars
anymore.
And so at some point it's possible, in fact,
likely that every galaxy in the universe that has
hydrogen in it will have lost all or most of that
hydrogen.
And when that happens, star formation is going to
ramp down and eventually stop billions of years
into the future, but not right now.
Will we be around billions of years in the future? No idea right now, will we be around billions of years
in the future?
No, I can't.
Come on.
Can I tell you?
Yeah, I can.
I can tell you.
I can tell you right now.
You know, you know, you got the answer now.
I got the answer right now.
Okay.
I see.
That's a great question though.
And these gas clouds that you see, are these
the same as stellar nurseries?
Is that what we.
That's exactly right.
Oh, okay.
Okay.
The nearest prominent one, you can see it with
the naked eye is the Orion nebula.
Right.
Underneath the three stars in the belt is this
lovely go glowing cloud.
And if you're in the Southern Hemisphere,
they're above the belt.
That is true.
And there's one-
So like us to hit below the belt.
And there's one star, one of those massive stars
that's doing all the ionization, all the excitation.
It is the guy that is responsible mostly for the
central part of the Orion Nebula looking like it
is, if it weren't there, it'd be a much less
interesting thing to look at.
Wow.
That is super cool, man.
All right.
This is a Christopher Peppers and Christopher says, hello, Dr. Shara, Dr. Tyson,
Lord Nice, Chris Peffers here from Charleston, Indiana.
Dr. Shara, you've spent decades studying exploding stars and binary systems, some of the most
extreme objects in the universe.
For people who might think space is just empty
and still, can you walk us through what happens in a close binary system where one of the
stars steals matter from another, eventually causing a supernova or a nova or a, or even
a supernova? What does that cosmic drama look like and should everyday people even care
about these distant events? Do they
help us understand our own sun or even where the elements that make up life on earth come
from? Thank you for your work, sir. There it is.
Well, first of all, it's my pleasure. I appreciate the pat on the back sort of the verbal pat
on the back. I do it, The reason I've spent decades doing this is
because I love it.
Uh, astronomy in some sense is my hobby.
Uh, the fact that someone's willing to pay me
to do it and to teach.
That's the old adage.
It is.
A hobby, make it a career.
It's.
And you'll never, was it?
Right.
Well, yeah, you'll never be something.
No, you'll never work a day in your life.
You'll never work a day in your life.
That's it.
And it's been a joy. And in some sense, I haven't worked a day in your life. That's it. Yeah. And it's been a joy.
And in some sense, I haven't worked a day in my
life because it's always been fun.
It's always been great.
And I get to work with lots of bright young people
doing their masters and PhDs and work with them
all the time.
So it's a glorious way to spend one's life.
Okay.
Let's zoom in on one of these systems, one of
these binary systems, and I'm going to pick
a particular system.
Okay.
That you're going to be able to see with
your naked eye next year or the year after.
Okay.
Okay.
All right.
Relatively short period of time.
I bet he's talking about T Corp on
the border house.
And Neil has just thrown a bone in his eye.
Don't tell anybody.
Okay, exactly right. And when he says it, just act. We'll act surprised. Act't tell anybody. Exactly right. But I think, stay quiet.
And when he says it, just act.
I will act surprised.
Act surprised.
Okay.
What is it?
So there is a star called T. Corona Borealis.
Oh, okay.
Woo.
Surprise.
That is going to get brighter than the North Star,
brighter than Polaris.
Wow.
Either tonight or tomorrow night
or sometime in the next year or two.
Okay, just, I have to jump in here.
So I don't want to cast shade on how bright it's going to get, but Polaris ain't that
bright.
Okay.
Our North Star.
I've heard you say this.
Even nine out of 10 people, you say, what's the brightest North Star?
They'll say North Star.
It is not in the top 10.
It's not in the top 20.
It's not in the top 30. It's not in the top 20. It's not in the top 30.
It's not even in the top 40.
Yes.
So I just put that out there right now.
And the Corbor, what is that reference?
Corona Borealis, Latin for a northern crown.
And it is a constellation, a little grouping of stars
that looks like a semiccircle, a crown.
Okay.
Gotcha.
That's a tiara would be that.
That's a better term.
It would be, wouldn't it?
Yes, exactly.
Much better.
So is there a crown in the Southern
hemisphere too?
There is Corona Australis.
Okay, good.
So that's why you specify the Borealis.
That is correct.
Yeah.
Okay.
So pick it, pick it up from there.
We saw this star last erupt about 79 years ago.
And then 80 years before that, we saw it
erupt as a Nova and each time it became about
second magnitude.
And one of my colleagues, Brad Schaeffer has
made a pretty good case for it having erupted
80 years before that.
And then he even points out some possible
evidence for an eruption in the 1200s.
So this is a star, this is a recurrent Nova.
Wait, nobody was looking up in the 1200s.
They were just trying to not whatever.
Not starve to death.
Get beaten by dragons or not starve to death.
Or die of the bubonic blade.
No, no, no, there were people who actually
did notice changing stars, things that were
wild and of course there were no electric lights in those days.
Yeah, you had a lot more stars to look at.
There were.
Actually, sorry, it was the 14th century, which was the only century where the population
of the world was lower at the end than it was at the beginning from bubonic plague and
all of this.
Yeah. Black Death will do it every time.
That's why I can't stand it.
They call it the black death.
Of course, the most deadly of deaths has to be
the black death.
No, go ahead.
I'm being silly.
Go ahead.
No worries.
So this star, this massive white dwarf is
cannibalizing its companion, which is a, in
this case, a red giant star.
Authentic red giant.
This is an authentic red giant.
Can you see both stars when you look at them?
Uh.
Were they too far away?
You can see neither.
It is roughly 13th magnitude in quiescence.
So if you look, uh, with a terrific pair of
binoculars, you still can't see it.
You need at least, if you want, uh, with a terrific pair of binoculars, you still can't see it.
You need at least, if you want to see it with your naked eye or with your eye,
you need at least say an eight or a 10 inch telescope to be able to see it.
Really good backyard telescope would catch this.
We'll see it when it's in quiescence and it's going to jump in brightness,
um, approximately a hundred thousand fold, uh, to reach roughly
the brightness, a little bit brighter,
probably than Polaris for a few hours.
Uh, and then it'll fade away.
And then on a time scale of a week or two,
you won't see it again.
Uh, and you won't see it again for another 80 years.
So when I was in the Pacific Northwest, I
took a photo of your star and I don't know
if I got to show it to you.
Did I?
Did I ever show it to you?
I think you might have.
Because there was a chance it could have blown up while I was looking at it.
Exactly.
And then I'd be the first to have seen it.
Or at least have recorded it.
I'd have been the first out of the box on that one.
Yep.
Everyone wants to be the one to see it starting on its rise.
Of course.
And so people have little charts and okay, there's T. Corona Borealis. So somebody's watching this thing every night. Of course. And so people have little charts and okay, there's T. Corona Borealis.
So somebody's watching this thing every night.
Of course.
Someone is watching it basically every minute.
24 hours a day.
24, 7.
Because half the world is dark at any given time.
And we got people everywhere.
Of course you do.
There are tens of thousands of so-called amateur
astronomers who are every bit as professionals, professional astronomers. In that community, it is a badge of honor to say I am an amateur
astronomer. If you say that, you can ask them any question about the night sky and they'll have an
answer. They know. Even some of my colleagues wouldn't know because they know the night sky.
They're out there every night as I was when I was, you know, had my backyard telescope, except my rooftop, right?
There's no backyard in the Bronx.
I was hauled to the roof.
So the thing for me that is most exciting
about T. coronaborealis is that as a recurrent nova,
it was predicted, and there were only 10 recurrent novae
known in the whole Milky
Way.
Okay.
About a decade ago, it was predicted that
boom, you blow off a shell of matter.
Then 80 years later, boom, you blow off
another shell, another, another, another.
The stuff doesn't all come off at the same
speed.
Some of it comes off at high speed, some
at a lower speed.
So what that means is when the next shell goes off. speed, some of it comes off at high speed, some at a lower speed.
So what that means is when the next shell goes off, someone's going to overcome.
It's going to, the fast stuff is going to over come the slow stuff.
Bingo.
So you're going to have shells colliding with each other.
Shells colliding, Jerry.
No, that's amazing.
And so it's going to be a traffic pileup.
It's like, you know, one car running into another.
And if that's right, that hasn't just been
happening for 80 or 160 or 240 or 320 years.
It's been going on for thousands or tens of
thousands of years, which means you've got
hundreds or thousands of shells piled up on top
of each other. That means you've got hundreds or thousands of shells piled up on top of each
other. That means you should have a super shell, a super remnant surrounding T. coronaburialis.
Where the fastest stuff is plowed onto itself. A bulldoze its way through.
But that's not all. Wait, wait, there's more because as that shell builds up in mass, it's also acting like a
snowplow plowing up all the stuff in the interstellar medium in front of it.
The stuff that's there anyway as bystanders.
Is going to get mowed over and is going to be incorporated into that super shell.
So there should be a super duper shell around
it and we've just found it.
Oh, he buried the lead.
What?
You heard it here.
So we've been using a gorgeous new, not
expensive telescope.
Oh.
The kind of telescope that so-called amateurs
use, refracting telescopes, six of them bolted
together in parallel, and we stared at T.
Corona Borealis for about a hundred hours.
They're not in darkness for a hundred hours.
Just want to make that clear.
Oh, okay.
Really?
Yeah.
They get the dark stuff tonight.
Right.
They close the hatch and then tomorrow night.
Pick it up again.
We're back at it.
Okay.
Back at it.
Okay.
Go.
And so we actually have thousands of images
taken over more than a hundred nights of T
Corona borealis.
And we add up all those images and we took
pictures through filters that only transmit the
light from hydrogen only transmits the light that
comes from nitrogen ions, sulfur ions and so on.
And we found a super shell surrounding
T.
Corona borealis.
That's about three times the diameter of the
full moon.
That's fabulous.
So it is a degree and a half on the sky.
And you might then think, well, when T.
Corona borealis goes off, it's going to be like a
flash bulb going off in the room, in a room full
of little mirrors. It's going to be like a flash bulb going off in the room, in a room full of little mirrors.
It's going to be like Christmas lights going off as this flash of light.
Right.
Propagates outwards.
Echoes off the material.
That's super shell.
One would hope that that would be true.
That's amazing.
It's probably not.
Oh no.
So the downer is we published in a paper that
just came out a couple of months ago saying
there's not going to be fluorescence.
Okay.
So the atoms themselves are not going to light
up because they're too far apart and there
aren't enough of them.
That's not going to be bright enough to detect
now, maybe just maybe if there was dust, little grains of silicon and carbon and other
what we call refractory elements, high temperature stuff, little grains that were tossed out
in the last nova eruption, the one 80 years ago, those might reflect enough light for
us to see as a light echo.
And you know that a day or two or three after this goes off, the Hubble Space Telescope
is going to get pointed at at the James Webb Space Telescope.
Yeah, we're very good about that.
Something happens, everybody comes together.
We are the most come together.
Shares information.
We are the most come together.
We're always about a collab-o.
Always, especially since not every telescope will observe it in the same way.
Yeah. So you get different kinds of data coming together
I always say the only people to collaborate more than rappers are astrophysicists
So Mike on my iPhone I
Controlled a digital telescope when I was in the Pacific Northwest didn't even leave the comforts of the living room when I did this
See he's he's old school. He's like what you didn't like ascend the mountain you
For that image I've been up in the prime focus
Nights at a time
Tell me about on your rocking chair
So this image I found it, but it was behind a very modeled tree.
And so the digital telescope tracks it.
But so the tree ends up blurred as it's tracking the actual object.
So it's a very undistinguished dot on my picture.
Had you caught it near its maximum, you would basically have saturated the image.
Yeah.
All of the image would be just one bright point of light.
Wow.
But there's no saturation anymore
because this knows what it's doing.
It takes 10 second images and then stacks them.
Right.
In the old days you expose it.
You overexpose.
Because you're absolutely, yeah.
Now you don't have that problem
because you're getting all separate images.
Separate images, then you stack them
and add them and you get it.
Keep going.
All right, let's keep going, man.
This is really cool stuff. This is Joel Bradley and Joel says, greeting Dr. Tyson, Dr. Shower, Lord Nice.
Joel here from Guilong, Australia, and I have a question regarding our favorite pre-Supernova
star Beetlejuice.
Boo.
Whilst I understand that life of a star is extremely long from our perspective, how is
the timeframe for Betelgeuse going to supernova between now and 100,000 years?
Is there any sign that will warn us of it happening in our lifetime or will we just
look up one night and go, oh wow, look at that?
There it was.
There it was.
What's the life expectancy of Betelgeuse,
from birth to death?
Something like, well, the star itself,
if you consider the main sequence lifetime,
probably a few million years.
Got it, okay.
So it was hydrogen burning for a good fraction
of its lifetime, maybe a million years,
maybe two, three million years.
When it's astrophysics speaking,
it means hydrogen fusion.
Right. Of course.
Okay.
So Betelgeuse was initially as a very
massive star fusing hydrogen into helium.
Then it left the main sequence, ascended
the red and then the red super giant
branches ran out of hydrogen and the core.
Ran out of hydrogen, needed to do something
else, needed a new source of energy.
Otherwise it was going to collapse.
The core got dense enough and hot enough
for helium to start fusing into carbon. new source of energy. Otherwise it was going to collapse. The core got dense enough and hot enough for
helium to start fusing into carbon.
And helium has two protons in its nucleus.
Now you've got to get two protons next to two protons.
You got to be hotter than whatever you were
for hydrogen.
Wow, look at that.
Typically you've got to be in the hundred
million degree range instead of the 20 million
degree range in order for that to happen.
Okay.
So it is really hot down there in the core of
Beetlejuice.
Beetlejuice has only got probably in the best
case, a hundred thousand years to go, but it
might be tomorrow.
Okay.
That's a really bad prediction.
Listen.
Can you do better?
Can you do better than that?
50 years ago, the prediction would have been,
we don't know why it's a red supergiant.
So we, so we have gotten a lot better.
Yes, we would love to do better.
And the answer is, we should, we should
appreciate how far we've come.
If you give me, if you give me enough money, I
will build a detector that will tell you
several days in advance when it's going to go off.
And what is that detector going to be?
Well, it's going to go off. Nice. And what is that detector going to be? Well, it's going to be the biggest, baddest
neutrino detector that's ever been built on earth.
Right now we've been super clever.
We, meaning physicists collectively, not me,
have built enormous detectors using cubic
miles of seawater or ice.
The ice cube detector, for example.
In Antarctica.
In Antarctica.
And a gorgeous detector right near Sicily,
a huge underwater detector.
And the wrapper ice cube goes down
there and performs for the scientists.
But if we could build a detector that was say,
Oh, a thousand times the volume.
So instead of a mile by a mile by a mile, we'd
love to build something that was 10 miles by 10
miles by, by a, by a few miles, at least, um,
we'd have a thousand times the sensitivity.
Now, why do I care about neutrinos?
Well, as the star is right near the end of its
lifetime and just about to flash off.
It's not just going to burn. Do you see the light?
Do you see the light?
Yep.
It's going to burn the carbon into magnesium,
the magnesium into heavier elements, all the
way up to iron.
And you're going to get a great flux of neutrinos
coming out of the core of the star in the last
few hours, maybe days of the life of the star,
certainly in the last couple of minutes.
And then during the implosion, you're going to
get another blast of neutrinos.
So these will come out of the star before
anything else.
Okay.
But they're not going the speed of light.
They're not.
So what it, so.
Doesn't matter.
And the reason it doesn't matter is that
beetle juice isn't that far away.
We're talking hundreds of light years.
We're not talking millions or billions of light years away.
And as a result, the difference between the speed of the neutrinos.
Which is very fast.
Which is very 99.9, many nines, the percent, the speed of light, the difference
in speed between the neutrinos and the
gravitational radiation.
Okay.
That will be.
And that's going to the speed of light.
That is moving exactly at the speed of light.
And we have something that could
detect that if it happens.
We have several detectors, at least three
up and operating now that are going to
detect those
gravitational waves.
Are they all collectively LIGO or is it just the
American ones called LIGO?
They're collectively called the LIGO and each one
of them has its own name.
For example, the Italian one is referred to as
Virgo, but the LIGO assembly is LIGO assembly is, is the three telescopes.
We get the gravitational waves and they will come at the same speed as the
explosive light, I presume.
They, they're going to proceed the light.
Oh, because you have the collapse.
You have the collapse and then you got to expand again to get big enough to have a
photosphere or radiating surface big enough.
So it's going to be tens of minutes to tens of hours before you see it in the
optical.
This is going to be amazing.
You'll see them right, one right after another, each of these,
the sequence of events.
So we're going to see the gravitational radiation and the neutrinos
arriving almost simultaneously.
gravitational radiation and the neutrinos arriving almost simultaneously.
We may get lucky and see a few of the early
neutrinos coming a few seconds or minutes early.
That would be just in the last gasps of, oh,
I'm just, I'm finished my carbon burning.
I'm going to do my magnesium burning.
That didn't help me.
I'm going to do my, my Silicon burn.
That helped me even less. I'm going to do my iron burning.
So you get more and more frantic.
I've never seen you imitate a star before.
That was pretty good. That was good. That was very good.
I was a dying star right there.
And so what he's doing is the star is trying to not die.
Right.
And so it's finding just finding everything it can do.
And if it can't, if it's not enough, it's going to collapse on there.
And so maybe in that last minute, we'll
start seeing a neutrino here, another one,
another one, another one, and then tens of
thousands of them arriving.
And that's going to be the herbinger.
That's going to tell us supernova coming.
Supernova is coming from there, that direction.
If we have all three detectors.
You can triangulate back on it.
We can triangulate to about plus or minus a degree.
Okay.
You know, a little bit more than the area of the full moon on the sky.
Yeah, but how many supernova progenitors are in the area of a full moon on the sky?
We typically get, you know, I mean, in a square degree, we've got millions and millions of
stars. You don't know which one it is, but if you triangulate back to that one square
degree where Beetlejuice is.
And Beetlejuice is in the middle of the thing.
Right.
That's pretty much another deal.
You should go whoop, whoop, whoop, whoop, turn on your alarms.
So how bright will Beetlejuice get?
Because it's already bright.
It's like, what is it?
It's, it's, it's zero magnitude.
What is it?
Maybe minus.
Minus one maybe. Something like that. It's certainly one of the, you know's, it's, it's zero magnitude. What is it? Maybe minus one, maybe something like that.
Yeah.
It's certainly one of the, you know, 15, 20
brightest stars in the sky.
Way brighter than the North star.
Once again.
So right now, currently it's maybe a million
times.
Yes.
The luminosity of the sun, but it's going to go
to at least 10 billion times.
It's going to get at least 10,000 times brighter.
Wow. Which means. That's 15 magnitude. It's gonna get at least 10,000 times brighter. Wow.
Wow, so that's 16 magnitude.
It's gonna be visible in daytime.
It's, oh, it's certainly gonna be a daytime thing.
It's gonna compete with the full moon for brightness.
That's great.
Probably cast your shadow.
No question. Oh my gosh.
No question.
Joel, there you have it, my friend.
If you have a neutrino detector,
you will know exactly when this is going down.
You'll know first. If you get the neutrinos and you get the
gravitational waves at the same time just know, Elizabeth I'm coming to join you honey.
Betelgeuse is about to kick the bucket and you can watch it. So that's cool.
One good piece of news, I mean you you're headed in absolutely the right
direction. I don't want you scaring anyone though. Okay. You don't need to go down to your basement or
your sub basement because even though there are
going to be lots of high energy neutrinos coming
and whacking you, none of them is going to hurt
you, there aren't going to be enough gamma rays
to fry our ozone layer.
Or make you the Hulk.
Or make you the Hulk or give you a sunburn.
So don't worry about that kind of stuff.
It's just going to be something ultra cool
that you can walk out and see something that
really nobody has seen since the 1600s.
We had two supernovas almost back to back.
Kepler had one.
Was that, how bright was Kepler's supernova?
It was also the same kind of brightness,
maybe not quite as bright as that.
In the daytime?
Uh, it was seen in the daytime, probably for a
month or two, but I gotta go check that.
So, um, let me ask you both of this then, uh, the
most famous star in the night sky and also
reportedly shown during the day, the star of
Bethlehem, do we have any real record of what that was? Go on, ask the Jewish man about the star of Bethlehem. Do we have any real record of what that was?
Go on, ask the Jewish man about the star of Bethlehem.
Go ahead.
So my forefathers did not draw a diagram or a map of where it was.
In fact, this only appears in the New Testament as a star in the East.
Star in the East.
You know, that's a little vague.
A little too vague, huh?
You think?
A little too vague, huh?
A little vague.
Yeah, gotcha.
And so what can we do that is maybe better?
Well, we can go back to the people.
That's all, that's the best info available.
That's it.
Well, we can try and cross correlated because
while the astronomers in, uh, the ancient Holy
land were not quite up to the task, there
were three sets of astronomers who were up to
the task and really were doing their jobs on a
night by night basis.
And these are the Imperial astrologers of
China, Japan, and Korea.
Okay.
Who were looking at the sky every night as
harbingers, either for good or bad.
Yeah.
Good or evil.
Yeah.
Because clearly the gods were up there.
Right.
And the emperor was a demigod.
Right.
So whatever was happening to the gods was
affecting the emperor.
So we'd better watch out really carefully
and write down what was going on.
And so from about 300 BC, but certainly from
zero BC onwards, there are pretty good nightly records in all
three kingdoms and the star of 1054, the,
what's today, the Crab Supernovas.
The Crab Nebula.
The Crab Nebula is detailed in great detail,
a wonderful detail in all three kingdoms records.
Wow.
So we know all about it.
So we know that it took place on July 4th, AD 1054. And astrophysicists to this day
celebrate with fireworks. If you see a launch of fireworks, that's what's going down.
That's so funny.
So you'd like to look for a…
So they would have had records for sure.
If there had been a really bright supernova
or a really bright Nova.
Anything.
Yeah, sure.
A bright Nova, a Nova that's only say a
hundred light years away.
And there are stars that are capable of
becoming novas only a hundred light years
away.
That is an easy star that can become
brighter than Venus.
So not quite a middle of the day, scary,
you have to death brightness, but still
pretty bright.
Still pretty bright.
So you gotta go look really carefully at
the Chinese, Japanese, and Korean records
from say minus 10 to plus 10, um, you know, AD, AD, and there is no good candidate.
And there's no good candidate.
Okay.
Wow, look at that.
And by the way, planetariums historically always had a Christmas show of the Star of
Bethlehem.
And was it a planetary alignment?
Was it Venus?
Was it this?
Was it that?
But it really wasn't any of those, right?
That's kind of a disappointing ending to a planetarium show.
But we would, we got so sick of the show. I mean, it was just not, there was no science in it. Yeah. And so in the, in the, in the parlance of planetary, you know what we call it?
The war on Christmas? No.
No, it was tradition. People come to see that and they go to the Rockettes.
Right. And that was, that would be the holiday thing.
That makes sense. No, but it became the SOB show.
SOB.
SOB standing for?
Star of Bethlehem.
There you go.
So we now have the technology.
Astronomers now have the technology to once
and for all answer the question.
Okay.
And I'm going to tell you how you heard it here
first.
All right.
Using the kind of telescope I described, the
one that found the super shell.
What question are we answering now?
Was there a star?
Sorry, Beth.
Was there a transient?
Was there a bright Nova or supernova?
Right.
Within say 10 years of zero AD.
Yes.
And we can actually answer that question
now quite definitively.
And within five to 10 years, certainly within 10 years, we're going to be able to give you that answer quite
definitively. Because you could. Because you are looking right now. Because you're going
to be, if it was something that exploded, you'd be able to see the remnant that's 2000
years old. And we're going to be able to track the expansion. Yes. And then track the expansion backwards.
Right.
To see when it's went off.
So you will know for a fact.
Oh my gosh.
And see, this is the cool thing about astrophysics because it comes with receipts.
You know what I mean?
You cannot bullshit.
This is Cicero Artifon.
What a cool name, Cicero.
We've had Cicero before.
Yeah, we've had them before.
Unless there's more than one Cicero out there, but I doubt it.
There ain't no two Cicero artifons, that's for sure.
Hi, Dr. Tyson, Dr. Shower, Lord Nice, Cicero Artifon here from the cold lands of Toronto,
Canada.
Brrr.
We use these incredibly bright supernovae as standard candles to figure out how far
away galaxies are.
But it feels a bit counterintuitive, doesn't it?
How can something so incredibly distant and that happened so long ago
act as a reliable measuring tape for the cosmos?
What's the ingenious method that allows us to use these far-off stellar explosions
to gauge such immense distances.
That's a terrific question.
These are the so-called type one a supernovae.
You weren't happy with just two types of supernovae.
Were you?
We had to subtype and subtype.
The type one A's are the magical supernovae
that give us.
Astronomers a yardstick.
We want to know how far away something is so that we don't just see how bright it is, but how energetic it is.
We can turn brightness into energy, into physical units.
Right.
And the type one a's are something that we call standard candles or equivalently standard
hundred watt light bulbs.
They're not.
Candles were quite honored that we use them in
this reference.
Yes, they did.
And they.
It's very classical.
Yeah.
Since they really suck as a light source, they
should be honored, but go ahead.
Well, the standard candle was made out of.
Whale blubber.
Oh, whale blubber.
A certain size.
The oil lamps.
Yeah.
I take it back then because believe it or not,
those actually burn pretty evenly in.
Well, if you have a big enough wick.
Yeah.
If you have a good one.
That was the point.
The beautiful thing about type one, a super
novice is not that they are really all exactly
the same
intrinsic luminosity, but because we're able to
measure the distances to some galaxies with
other tools that we believe in very firmly,
especially the Cepheid variable stars, and now
the so-called tip of the red giant branch stars.
We have a few hundred galaxies whose distances
we know with great accuracy.
Nearby.
Nearby.
Out to perhaps 50 million light years.
That's nearby.
Okay.
50 million light years.
Far back, far back.
Let's go there tomorrow.
And we see type one A supernovas going off there
and we can measure their light curves, their
brightness as a function of time, very precisely.
And then we put them on the same graph and we see that the brighter ones also last longer.
But when we collapse them down to the same width, in other words, if we just shrink them digitally, both in brightness and in width, they all
lie right on top of each other.
So they are standardized bull candles, standardizable hundred watt light bulbs.
That makes that.
So the thing we can measure easily is how long they take to fade.
Yeah.
And then we use that, how long they take to
fade information to crunch down the light curve
onto the standard light curve.
And then we can look at supernovas that are 10 or
20 times further away than the furthest Cepheid.
And that's how we can step way outside our backyard.
So it relies on the nearby calibrations basically to trust what the extrapolation is going to be.
And then you get far enough out to say, good grief. We thought the Hubble constant
meant that the universe was always expanding at the same rate. Everything is cool. It ain't so.
was always expanding at the same rate. Everything is cool.
It ain't so.
We have a change.
We have an acceleration in the expansion
of the universe.
Where did that come from?
Who ordered it?
The so-called dark energy.
Right.
We have no idea what it is, why it's there,
et cetera, et cetera, but it seems to be there.
And that's because of the type one, a super
name.
Right.
Because you know, because of your standardizable, uh, um, uh, candle
system that it works all the way out to here.
It's just that when you got to that point beyond that, that's when things change.
Well, something had to change because everything else going, coming from this
point forward to us still works.
Pete Everything still works. The physics is fine.
Pete Physics works, but it allows us to implicate the universe and not to stand or care.
Pete That's the point. Yeah, that's amazing.
Pete And to answer the second part of the question,
how did the universe figure out to do something like this? It turns out to be these wonderful white dwarfs, these collapsed objects
actually have a maximum possible mass.
They can't get more than about 1.4 times the mass of the sun.
If they do, then the gravitational forces within cannot be resisted by any pressure
force without.
And so there is a magic number.
They actually calibrate themselves for you.
That's amazing.
Oh my God, science is so crazy. No, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no, would blow up at different masses. You don't know what you're looking at.
But everybody's blowing up at the same mass.
It's just a little more complicated than that,
but here's the one caveat.
I was proud for a second.
Because you can have two white dwarfs,
a binary white dwarf merge,
and then you can be anywhere between 1.4
and 2.8 times the mass.
So that's a.
That would still count as a 1A supernova.
That'll still count as a 1A.
And that's why you have brighter ones and fainter ones and shorter decay times and longer
decay times.
Cause you have the little guys at the 1.4 and the bright, bright guys at 2.8.
Okay. Okay.
Okay.
And we've learned how to calibrate for that.
Okay.
Little extra complication.
So that's happened since I've been in graduate school.
I don't think we knew that back in my day.
Nope.
Right.
Now, so my little contribution to this.
Go ahead.
I am last author on a paper.
Okay.
Last but not least. Last author on a paper. Last but not least.
Last author on a paper. The first author was
Brian Schmidt. Nobel Prize winner.
Nobel Prize winner for co-discovering the dark
energy with supernova type 1a. I'm on one of his
supernova papers. We, very proud of this,
it is a supernova whose light curve
does not fit the light curve of other supernova
that it's supposed to,
until you invoke the expanding universe time dilation
on its light curve.
There you go.
And then when you mathematically remove the time dilation of the light curve,
it falls right back on Q.
Super cool.
So you get its distance and its speed with which it's receding and that rate stretches
out the light curve.
And so it was the first paper to demonstrate that and now it's a routine correction that
you make.
So let me just see if I got this right. The stretching of space is really what makes the
difference.
Yes, and the stretch of space also stretches the time frame. That's correct.
Why are you smart, man?
Well, there's 15 other authors on it.
They were all brave because the first time you publish something wildly different
from what anyone else has ever seen, there's always this little nagging voice in the back
of your mind, did I screw up somewhere?
They're all going to laugh at you.
Am I going to be a laughing stock?
Is this interesting result of me screwing up?
Right. Right. Because if it matched other results, you all couldn't of me screwing up? Right. Right.
Right.
Because if it matched other results, you all couldn't have screwed up in the same way.
Right.
Right.
Right.
So just to be clear about the timing.
So if you are receding and you're sending one pulse per second, let's say, but you're
receding, the next pulse will not get to you after a second, it's a little longer.
Exactly.
Because you're now farther than when you had sent the first pulse.
And so that in a timed light curve will stretch out the light curve, that's all.
And so this got corrected for and there it was.
I mean, you say it like it's nothing, but I mean, that's pretty elegant if you think
about it.
It was.
And he went on and got a bunch of these and got the Nobel prize and that was it. Cool. Deservedly so.
I didn't get an invitation to the Nobel prize.
Oh well, listen, it's in the mail.
Michael, I think we have to quit it there.
Wow, that was great, man.
I mean, you're such a good talker, we didn't get to as many questions as we might have.
Sorry about that.
But they were good questions.
Yeah, they were great questions and great, great answers. And I learned a lot. So, well,
this is, this is, I don't know. I can, I can, I can actually, uh, tonight, uh, when I take my
edible, I can think about all of this. I can think about all of this and really just like marinate.
Just before you do though, I want you to check whether T-Core Borer has exploded.
Oh, I'll do that first. You have to look out your window.
First I'll check my neutrino detector.
Otherwise you may see three or four T-Core Bores when you look out the window.
All right.
Thanks friend and colleague Michael Schara.
Great pleasure.
Thank you.
Chuck.
Always a pleasure.
All right.
This has been yet another episode of Star Talk Cosmic Queries, the Exploding Stars edition.
Oh yeah.
Neil deGrasse Tyson bidding you as always to keep looking up.