Quand les étoiles se rapprochent vraiment les unes des autres, c'est comme si elles s'embrassaient dans un baiser cosmique. Ces baisers d'étoiles peuvent provoquer d'énormes explosions appelées supernovae, illuminant le ciel d'une luminosité incroyable. Parfois, les étoiles peuvent fusionner pour former une étoile encore plus grande. D'autres fois, elles peuvent créer un objet super-dense appelé trou noir. C'est un événement cosmique étonnant qui montre à quel point notre univers est puissant et dynamique! Animation créée par Sympa.
----------------------------------------------------------------------------------------
Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
----------------------------------------------------------------------------------------
Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
----------------------------------------------------------------------------------------
Si tu en veux encore plus, fais un tour ici:
http://sympa-sympa.com
----------------------------------------------------------------------------------------
Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
----------------------------------------------------------------------------------------
Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
----------------------------------------------------------------------------------------
Si tu en veux encore plus, fais un tour ici:
http://sympa-sympa.com
Category
😹
FunTranscript
00:00Viewed, it would seem that two giant stars have been surprised in full romantic kiss.
00:05Although it may seem to be only paparazzi swans at first glance,
00:10it is actually a fascinating cosmic phenomenon discovered by an international team of astronomers.
00:17The life cycle of a single star is relatively simple.
00:21They are born in huge gas regions of space, burning their fuel,
00:25then, at some point, they explode in supernovas.
00:29But when stars are born close to each other,
00:33their mutual gravitational attraction can captivate them in what seems to be an eternal dance.
00:40Sometimes, they get so close that they almost seem to touch each other.
00:45These stars can spend billions of years spinning around each other.
00:49But their kiss only lasts a few million years, which is only a wink at the scale of the cosmos.
00:56Leonardo Almeida, the main author of this study,
01:00set out to find binary stars trapped in this cosmic kiss.
01:05He focused his research on the Nebula of Tarantula,
01:08a magnificent region of star formation located in the Large Magellanic Cloud,
01:12160,000 light-years from our planet.
01:15And there, he discovered the sparkling binary star system,
01:18called VFTS 352, which stood out from the others.
01:24The two discovered stars were quite large and almost identical in size.
01:29Together, they form a mass about 57 times greater than that of our Sun.
01:34Before that, only three other large-mass binary systems had been discovered.
01:39Since these two stars were so close,
01:42they generated an intense gravitational attraction
01:46that made them orbit around each other at a stupefying rate of one revolution per day,
01:51separated by barely 12 km.
01:54With such proximity, they formed a bridge allowing their stellar fuel to mix,
02:00thus sharing nearly 30% of their total volume.
02:03The temperatures of this system were also unparalleled
02:06and reached 41,000 degrees.
02:10At first, it seems that the internal mixture of their energy
02:13could allow these stars to live longer,
02:16by burning more fuel over prolonged periods.
02:19But this benefit would only be temporary.
02:22Two probable scenarios are drawn for their fate.
02:26They could merge to form a giant star, which would explode into a supernova,
02:31or they could explode separately
02:34and end their days as black holes orbiting around each other.
02:41If they merged, this process would take about 600,000 years,
02:45while if they became a system of binary black holes,
02:48they could continue to burn for another 3 million years.
02:51However, the two scenarios would ultimately lead to their destruction,
02:55unless they turned into two distinct black holes,
02:59drifting in opposite directions through the vastness of space,
03:03a possibility that is also conceivable.
03:08Recently, astronomers from all over the world attended a stunning show.
03:12Jupiter and Venus, the two brightest planets in the night sky,
03:17were so close together that they seemed about to collide or kiss.
03:22At least, that's what it looked like from Earth.
03:25In reality, they are still separated by 643 million kilometers.
03:31Another fascinating subject for astronomers concerns the G objects.
03:35They are celestial objects that look like clouds of dust and gas
03:39but behave like stars.
03:43In the center of our galaxy, there is a supermassive black hole,
03:46Sagittarius A, with a mass 4 million times higher than that of our Sun.
03:51And recently, scientists discovered two mysterious objects,
03:55called G objects, close to this black hole.
03:58They are G1 and G2 objects.
04:02The most likely theory is that G2 is made up of two stars
04:06orbiting around the black hole in tandem
04:08before merging into a single huge star
04:11enveloped in an exceptionally thick cloud of gas and dust.
04:16When G2 approached the closest to the black hole,
04:19it emitted a strange signature, stretching and losing a large part of its gas.
04:24As it approached the black hole, it lost its outer envelope
04:29and became more compact.
04:33What particularly excites astronomers about G objects
04:37is the material that is ripped off by tidal forces
04:40when it passes near the central black hole.
04:43This material inevitably ends up being sucked by the black hole,
04:47creating a real pyrotechnic show.
04:51This happens because the material consumed by the black hole heats up
04:55and emits radiation before disappearing through the event horizon.
04:59This horizon is the formidable limit of a black hole,
05:02beyond which nothing can escape.
05:07It now seems that scientists have discovered four other G objects,
05:11G3, G4, G5 and G6.
05:14All are located less than 0.13 light years from the black hole.
05:18It could be that these six objects once belonged to binary systems
05:22that have come together until they merged
05:25due to the powerful gravity of this massive black hole.
05:28Usually, it takes more than a million years
05:31for the fusion process between two stars to end.
05:34We hope to discover more G objects,
05:36because it gives us one of the rare opportunities
05:38to study the behavior of matter close to a supermassive black hole
05:41without it being immediately swallowed.
05:44At least, for the moment.
05:47Have you heard of variable stars?
05:50When we look at the sky,
05:52we often imagine that stars are points of immutable and eternal light.
05:56But if some stars seem to be constant,
05:59others change their luminosity over time, hence their name variable stars.
06:04Some of them go out and come back on for periods
06:07ranging from a few days to several years.
06:09These variations are not visible to the naked eye.
06:12Only astronomers, thanks to their sophisticated equipment
06:15and their long-term observations, are able to detect them.
06:20And what about vampire stars?
06:22Imagine two stars in a binary system,
06:25a red giant and a white dwarf
06:27spinning around each other like cosmic ballet dancers.
06:32The red giant, formerly a vibrant star,
06:35has aged and weakened.
06:39Its external layers of hydrogen,
06:41formerly firmly held by its gravity,
06:43have relaxed, making it vulnerable to the greed of the small and dense white dwarf.
06:49The white dwarf, nicknamed vampire star,
06:52convoys the fuel of its big sister
06:54and sees an unexpected opportunity there.
06:58As they dance together,
07:00the vampire star uses its powerful gravitational force
07:03to siphon the hydrogen from the red giant's external layers.
07:07It then shines in a blue hue
07:10and seems to rejuvenate and overflow with energy
07:12as its rider turns gray.
07:17But there are more than vampire stars.
07:19There are also zombie stars.
07:22Sometimes, when a red giant explodes,
07:25it does not disintegrate completely.
07:28Instead, a remnant of the white dwarf subsists after it,
07:32comparable to a zombie star that was dead but has now come back to life.
07:38However, this zombie star does not have a brain like in the movies,
07:42but hydrogen itself that the vampire star has been stealing from it since the beginning.
07:46If the zombie star is close enough to its former partner,
07:50it will begin to suck up matter to resuscitate its nucleus.
07:55It will then become a hydrogen bomb,
07:57ready to explode in a formidable show of cosmic revenge.
08:04It is a fascinating phenomenon that we generally do not detect
08:07because these explosions are much weaker than the usual supernovas.
08:11But when they occur,
08:13the detonation that results from it is truly daunting
08:17and destroys both the vampire star and its zombie twin.
08:21It would seem that vampires and zombies
08:23are not just fictional characters after all.
08:27Not only are we made of star dust,
08:29but we also have more in common with stars than we thought.
08:34Thus, stars also like to stay in groups with their loved ones,
08:38and most stars prefer to travel through the universe in clusters.
08:42These stellar clusters are groups of stars gravitationally linked to each other.
08:47Those that are there are generally the same age and the same type,
08:51sharing the same hobbies and the same centers of interest.
08:54Perhaps they even have a more active social life than ours.