Did you know there are stars in our galaxy that are moving so fast, they can actually escape the Milky Way? These super-speedy stars, known as "hypervelocity stars," are traveling at millions of miles per hour! They get this incredible speed from intense cosmic events, like a supernova explosion or getting slingshotted by the supermassive black hole at the center of our galaxy. Once these stars pick up enough speed, they can break free from the Milky Way’s gravitational pull. Scientists have discovered a few of these runaway stars, and it’s wild to think they’re zooming off into intergalactic space. Who knows where they’ll end up next! Animation is created by Bright Side. ---------------------------------------------------------------------------------------- Music from TheSoul Sound: https://thesoul-sound.com/ Check our Bright Side podcast on Spotify and leave a positive review! https://open.spotify.com/show/0hUkPxD34jRLrMrJux4VxV Subscribe to Bright Side: https://goo.gl/rQTJZz ---------------------------------------------------------------------------------------- Our Social Media: Facebook: https://www.facebook.com/brightside Instagram: https://www.instagram.com/brightside.official TikTok: https://www.tiktok.com/@brightside.official?lang=en Stock materials (photos, footages and other): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ---------------------------------------------------------------------------------------- For more videos and articles visit: http://www.brightside.me
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00:00At first sight, it looks like any other star, until you glance away just for a second.
00:06You look back, but the star is nowhere to be seen.
00:09All because it's likely the fastest star out there.
00:13Now hear me out.
00:15Astronomers have recently discovered an astonishing new class of stars.
00:18They got the name hypervelocity stars.
00:22Scientists have spotted around a dozen of such stars.
00:26And it turns out that they're so speedy that they can leave our home Milky Way galaxy one
00:31day and set off on an intergalactic journey.
00:35You see, stars do weave in and out of the Milky Way galaxy's spiral arms all the time.
00:41Like hurrying cars speeding through rush hour traffic.
00:44But when you look at the night sky, it may seem that these bright spots are as stationary
00:50as the monumental pyramids of Giza.
00:53Now among those 200 to 400 billion stars that call the Milky Way their home, there
00:59is a tiny, tiny fraction that stands out.
01:03Gravitational interactions have sped those massive stars up so much that they started
01:07moving twice or even three times faster than our Sun.
01:12Yep, these are the very hypervelocity stars bound to break free of the gravitational embrace
01:18of our galaxy.
01:20They seem to be trying to take speeds to a new level.
01:24They move at a speed of more than 700,000 miles per hour.
01:28A hypervelocity star could zip from the Moon to our planet in a mere 20 minutes.
01:34They are solitary stars, very different from previously discovered ones.
01:40The original hypervelocity stars are large and blue, and seem to be born in the core
01:46of the galaxy.
01:47As for the new stars, they are quite small, not bigger than our Sun, and don't seem
01:52to come from the galactic center, which is surprising.
01:55Instead, they are often caught fleeing youthful clusters.
02:00Most hypervelocity stars are in the Milky Way galaxy's outer halo, about 150,000
02:06light-years away from the galactic center.
02:09Interestingly, an astronomer at the Los Alamos National Laboratory in New Mexico predicted
02:15the existence of hypervelocity stars in 1988, but scientists didn't find any of them until
02:232005.
02:24The first star to be spotted was 350,000 light-years away from the core of the Milky Way and moved
02:31away from the center of the galaxy at about 1.5 million miles per hour.
02:39Astronomers say that it's extremely difficult to kick a star out of the galaxy.
02:43One of the most common mechanisms for doing so is some kind of interaction with a supermassive
02:49black hole at the galactic core.
02:52So Sagittarius A, which might be the very black hole we're looking for, at the center
02:57of the Milky Way probably accelerates hypervelocity stars, or at least some of them.
03:03To reach escape velocity, a star must get a more than a million-mile-per-hour kick.
03:09And since the Milky Way's central black hole has a mass of 4 million suns, it has enough
03:14power to produce something like that.
03:17The most typical scenario involves a binary pair of stars.
03:22This is a system of two stars that are gravitationally bound to and in orbit around each other.
03:29So let's say these stars get caught in the grip of our black hole, and as one of the
03:33stars is spiraling inward towards the black hole, its sibling is flung outward at a tremendous
03:40speed.
03:41This is called a three-body exchange.
03:44Astronomers have already found 18 giant hypervelocity stars that could have been produced by this
03:51mechanism.
03:54There's also a theory that hypervelocity stars might be ejected from dense stellar clusters
03:59by supernova explosions.
04:02The newly discovered hypervelocity stars seem to have the same composition as regular stars.
04:09That's why astronomers don't think that their birthplace could be some exotic place outside
04:13the galaxy or in the outer halo of the Milky Way.
04:17The thing is, it's a lifeless region full of old, metal-poor, and low-mass stars, and
04:23it's impossible to see a hypervelocity star there unless it was ejected in that direction.
04:30So hypervelocity stars still remain a mystery for us, but they're not the only stars out
04:36there that act weird.
04:38For example, in 2017, astronomers spotted a bright star hurtling out of the Milky Way.
04:45It was moving incredibly fast, at a speed of 2 million miles per hour, which is almost
04:50four times as fast as the Sun orbits around the center of the Milky Way galaxy.
04:56Anyway, the main issue with the wandering star was that it was moving against the direction
05:01in which most stars travel around the center of our galaxy.
05:06And it wasn't the only bizarre thing about it.
05:08Its appearance evoked a lot of questions.
05:11Was it a hypervelocity star?
05:14Was it even a star?
05:15The space traveler consisted of totally different star stuff.
05:20Astronomers managed to identify its composition.
05:23It was made up of heavy metallic atoms.
05:26Most other stars consist of way lighter elements.
05:30The wandering star got its name LP40-365.
05:35It was moving so fast that it literally dashed out of our galaxy.
05:40This made scientists believe that it was pushed out of its place by some kind of cosmic disaster,
05:46like a supernova.
05:48These days, astronomers claim that the star, which was previously considered to be a white
05:53dwarf, is actually a piece of star shrapnel.
05:57Kind of a leftover after a more massive star experienced a supernova.
06:02The explosion must have been so powerful that it pushed LP40-365 into interstellar space.
06:10This piece of a previously glorious star keeps slowly rotating around its axis.
06:17This is more proof astronomers need to claim LP40-365 is indeed just a chunk of space debris
06:24and not a full-fledged star.
06:27But such a conclusion means that it has witnessed a supernova.
06:31Even though this event happened lightning fast, the entire makeup of this space object
06:36was changed.
06:39You see, most stars consist mainly of helium and hydrogen.
06:43But LP40-365 is different.
06:46It contains such heavy elements as magnesium, oxygen, and neon.
06:51It must have been the supernova that added these atoms to the star's composition.
06:56By the way, astronomers considered all elements that are heavier than helium to be metals.
07:01This means that after witnessing the supernova, LP40-365 became metallic.
07:08Our space traveler brightens and then dims again every 8.9 hours.
07:13It might mean that the star pulsates, but usually stellar pulsations are much less regular.
07:19A more plausible explanation is that the star's surface is uneven, and as it spins, sunspots
07:25are brought into and out of view.
07:28Let's move to another unusual space body.
07:31It's the 18th brightest star in the night sky, and it's called Fomalhaut.
07:36If you look at it through a telescope, you'll be met by a terrifying sight.
07:41No wonder it's dubbed the Eye of Sauron.
07:44A ring of dust and debris circles it, making it look like a giant eye staring straight
07:50into your soul.
07:51The intimidating star is more than twice the mass of our sun and is 25 light-years away
07:56from Earth, which isn't that far away considering distances in space.
08:01Then there's a star that is tearing itself apart.
08:04It has a beautiful name, Vega.
08:07At first sight, it seems to be normal, large, bright, and pretty young.
08:12But the deeper you go, the weirder it gets.
08:16For example, it's not actually round, it looks like an egg.
08:21It might be because the star rotates so fast that its shape gets distorted, causing temperature
08:26variations across Vega's surface.
08:30It's also going 93% of the maximum velocity a star this big can handle, and I mean a mind-boggling
08:37170 miles per second!
08:41Astronomers aren't sure why Vega is rotating so fast that it's almost tearing itself apart.
08:47Mira is sometimes one of the faintest and sometimes one of the brightest stars in the
08:52night sky.
08:53This system actually consists of two stars.
08:56One of them is a red giant that once resembled our sun.
09:00The other is a white dwarf.
09:02The red giant is constantly shredding its outer layers, creating clouds of debris around
09:07the whole system.
09:09This phenomenon might be the reason for the regular dimming of the stars.
09:13It can also explain why the intervals between these periods of dimming aren't regular.
09:18But the coolest thing?
09:19It gives the stars a comet-like tail!