Not a Star Not a Planet Yet Hotter Than the Sun

Bright Side

There’s a bizarre object out in space that’s not a star and not a planet, but it’s hotter than the Sun! It’s called a “brown dwarf,” sometimes nicknamed a “failed star.” Brown dwarfs are too small to start nuclear fusion like real stars, but they’re much bigger and hotter than regular planets. One brown dwarf, called WD 0032-317B, is especially strange because it gets heated up by a nearby white dwarf (a super-hot leftover core of a dead star). This makes its atmosphere reach temperatures of over 14,000 degrees Fahrenheit, hotter than the surface of our Sun! It’s a wild example of how weird and surprising the universe can be.

Transcript

00:00Okay, it seems scientists have come across a strange object in space, and they're not

00:05sure if it's a star or a planet.

00:08What we do know is that it's located 1,400 light-years away from us.

00:13And it makes us question what we thought we knew about the universe.

00:18Let me explain the dilemma here.

00:20We can tell if something is a star or a planet by considering the object's mass or the amount

00:25of stuff it has.

00:29Stars have a lot of mass, which gives them strong gravity that squeezes them tightly.

00:35Squeezing creates high temperatures inside them, causing them to shine brightly.

00:41Planets have less mass, so their gravity is weaker.

00:44They don't experience the same squeezing or high temperatures as stars.

00:48Instead, planets shine because they reflect the light from their stars, like our beautiful

00:53Earth does with our sun, too.

00:56And this weirdo falls somewhere in between, since we consider it a brown dwarf.

01:01That's a special type of big, gaseous protostars.

01:05Brown dwarfs are usually like Jupiter in terms of their atmosphere.

01:10But they are much larger in size, about 13 to 80 times.

01:14If a brown dwarf has more than 80 times the mass of Jupiter, it can start burning regular

01:19hydrogen, just like a star.

01:21That's what usually makes stars shine brightly.

01:25But normally, brown dwarfs are not as hot as stars.

01:30Their inability to burn hydrogen has even earned them the nickname of failed stars.

01:35They burn at around 4,000 degrees Fahrenheit, which is cooler than most stars.

01:42But this object defies the norm.

01:44Its temperature measures an incredible 13,900 degrees Fahrenheit.

01:49Now, let's put that into perspective.

01:52The hottest day in history was reported to happen in Death Valley, California, more than

01:57a hundred years ago.

01:58With a temperature of 134 degrees Fahrenheit.

02:02People back then must have felt like they were melting, along with everything around them.

02:07Now imagine getting closer to the Sun, like taking a trip to Venus.

02:12Venus can reach insane temperatures of 860 degrees.

02:17It's not only about the distance, though.

02:19Mercury is the planet closest to the Sun, but it's still colder than Venus.

02:24Venus is extremely hot due to the greenhouse effect.

02:28Did you know that Venus could have been a delightful place to live a long, long time ago?

02:33Or at least, be home to any form of life.

02:36But at some point, it started to trap carbon dioxide and eventually created this thick, smoggy

02:42oven that doesn't release heat.

02:45And that's why it's so hard to explore.

02:47The longest a probe managed to last on Venus was two hours.

02:51But hey, that's longer than I can do at work, and then I melt.

02:59So yeah, then you get to the Sun.

03:01Its surface burns at an incredible 9930 degrees Fahrenheit.

03:07And what's fascinating is that this weird brown star we're talking about is hotter than

03:12that.

03:13It's not hotter than the Sun's core, whose temperatures go up to 27 million degrees, but

03:18it's still very impressive and unusual for a brown dwarf to be this hot.

03:23At least, that's what everyone thought until they realized why it was happening.

03:28The brown dwarf is remarkably close to another star that falls into the category of white dwarfs.

03:34They're so close to each other that our mysterious star makes one orbit around its white dwarf friend

03:40in just 2.3 hours.

03:42Woo!

03:43How old we'd be over there!

03:46Since they're this close, they're tidally locked, like our Moon and Earth.

03:50That means one side of this brown dwarf always faces the white dwarf, and the other side is

03:56forever in darkness.

03:58Because of all this, our brown dwarf is superheated on one side only.

04:03So its day side is what got us confused.

04:07While the temperature on the night side is what you would expect from a brown dwarf.

04:12But these extreme conditions won't last long.

04:15Such a hot temperature makes the molecules in the dwarf's atmosphere break apart into individual

04:21atoms.

04:22And while its molecules are falling apart, this brown dwarf is slowly disappearing.

04:30And if you think this brown dwarf is high, what would you say about Eta Carinae?

04:34It's a star located about 7,500 light-years away from Earth.

04:40And it belongs to an elite group of stars we call luminous blue variables.

04:46One astronomer first noticed it in the 17th century.

04:49But back then, it was just a regular medium-bright star.

04:55Almost 200 years later, another astronomer was observing it.

04:59But this time, it was a very bright star, one of the brightest ones in the sky.

05:04A few years later, it reached the highest level of brightness in a big event called the Great

05:09Eruption.

05:10When it happened, the star could be easily seen in the night sky.

05:14It released so much light, as much as is emitted in a supernova explosion.

05:19It remained like that for a couple of years, which is not what usually happens with exploding

05:24stars.

05:25After the party reached its peak, the star decided it was time to leave.

05:30It's still hesitating, though, so it's still alive but dimmer than before.

05:36There's a nebula around Eta Carinae, too.

05:39It is a shell made of gas and dust that formed during the Great Eruption.

05:43It even blocks some of the star's light.

05:46Eta Carinae is a binary star system.

05:49That means there are two stars that orbit around each other.

05:53One component has a temperature of about 26,500 degrees and the other 62,500 degrees.

06:02The main star in the Eta Carinae system, which is the more massive of the two, is 100 times

06:08heavier than our Sun.

06:10Because of its enormous mass, scientists predict that this star may eventually explode in a

06:15powerful event known as a supernova.

06:19But not for another several thousand years.

06:24So by now, you might have already guessed what the hottest thing in the universe is.

06:29Ta-da!

06:30A supernova.

06:32The supernova is what tells us that the life of a star has ended.

06:37We're talking about the most powerful explosions in space.

06:41They happen when a star that's between 8 and 40 times more massive than our Sun flops.

06:47Its core can no longer create enough energy through a process called fusion.

06:52So the star can't even handle its own gravity.

06:55It's like a stellar burnout.

06:57Too much work a star can't handle, and its core just collapses.

07:01During a supernova, the temperatures in the star's core can get 6,000 times higher than

07:07in the core of the Sun.

07:08Or sometimes, a specific type of star called a white dwarf suddenly restarts its nuclear

07:14fusion, and bam, you get a supernova again.

07:19Kepler's supernova happened at the beginning of the 17th century.

07:24And it was the last, really big supernova event we directly observed from Earth.

07:29On average, supernovas in our galaxy happen three times every century.

07:34I mean, we got a smaller supernova in 1987, too, when a blue supergiant exploded in one

07:41of the Milky Way's satellite galaxies, which we know as the Large Magellanic Cloud.

07:49This explosion was so strong, people could even observe it with the unaided eye, even though

07:54it was incredibly far, 168,000 light-years away from our home planet.

08:01What a topic for summer days, huh?

08:03But check this out.

08:04We can also talk about the hottest thing people have ever created, made in a surprising place,

08:10Switzerland.

08:11Nah, we're not talking about a superhot chocolate.

08:15A group of scientists there created a subatomic soup called a quark-gluon plasma.

08:20In this experiment, the temperature got 250,000 times as hot as the Sun's core.

08:26The purpose of this experiment was to recreate the conditions that existed shortly after the

08:31Big Bang, when the Universe was still in a state of chaos.

08:36Okay, let's get even more extreme.

08:39In theory, things can get even hotter.

08:43Have you heard of the Planck temperature?

08:44It's an insanely hot temperature with numbers so high we can't even imagine.

08:51A supernova is like tepid tea compared to this madness.

08:55And who even knows what the matter does at these temperatures?

08:59Okay, I'm done.

09:01Now we take you back to your regular universe.

09:03Bye now!

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