Category: Cosmology

milky way galaxy

Milky Way : a huge explosion 3.5 million years ago

– News of October 15, 2019 – Until recently, it was thought that the central black hole of the Milky Way, called Sagittarius A*, was a small supermassive black hole. With 4 million solar masses, it is not one of the big supermassive black holes. Its activity seems weak, nothing to do with the overpowering…
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expansion of the universe

Expansion of the universe, dark energy : the challenges of DESI

– News of October 13, 2019 – Dark energy is one of the toughest puzzles in modern physics. For twenty years, a series of measures seem to show that the expansion of the universe accelerates over time. Since none of the four fundamental forces allowed by physics can explain this phenomenon, so far the phenomenon…
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black holes

A tiny black hole in the solar system ?

– News of 1st October 2019 – For five years, some astronomers have speculated that there is a ninth planet in the solar system. They support this prediction on the observation of the trajectories of certain Transneptunian objects. These small planetoids orbit the sun at a great distance, much further than Neptune or even Pluto.…
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supermassive black hole

All about supermassive black holes and news

More details on the strong activity of the supermassive black hole Sagittarius A* – News of September 29, 2019 – Sagittarius A*, the central black hole of the Milky Way, is usually quite calm, at least for a black hole of several million solar masses. It has been under regular surveillance for a quarter of…
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supernova

All about supernovas and news

SN2016iet, a supernova like no other – News of August 27, 2019 – The core of the stars is the place of a perpetual struggle between the radiative pressure of the thermonuclear reactions that grow outwards and the gravity that seeks to bring everything back to the center of the star. The equilibrium point is…
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frb fast radio bursts

All about fast radio bursts (FRB) and news

For the first time, the source of a unique fast radio burst has been identified – News of July 2, 2019 – In 2007, while digging into old archives of the Parkes observatory in Australia, a student made a strange discovery. The radio telescope appeared to have recorded a very short radio burst in 2001…
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stars

All about stars and news

The star HR9024 loses weight due to incredible coronal mass ejections – News of June 11, 2019 – Observed from afar, the sun may seem like a shiny, smooth ball. Modern astronomy has shown that in reality the surface of our star is covered with bubbles and filaments, some of which may be absolutely gigantic.…
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galaxies

Galaxies : all you have to know and news

Giant galaxies put the size of the Milky Way in perspective – News of May 28, 2019 – In comparison to the dwarf galaxies that surround us, the Milky Way and Andromeda may seem immense. Their diameter is indeed spread over hundreds of thousands of light-years. But if you search the whole observable universe, you…
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Antimatter : all you have to know and news

Italian researchers succeed in interfering with antimatter – News of May 21, 2019 – In 1923, the French physicist Louis de Broglie published a surprising article. He formulates the hypothesis that matter has an associated wave. Over the next few years, this was confirmed when researchers succeeded in interfering with electrons, protons and even whole…
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neutron stars

All about neutron stars and news

LIRGO and VIRGO detect the meeting of a neutron star and a black hole – News of May 7, 2019 – In 2015, the first gravitational wave was observed, nearly a hundred years after Albert Einstein predicted their existence. Gravitational waves are oscillations in the curvature of space-time. They occur when masses are accelerated. These…
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wormholes

Wormholes : all you have to know and news

Wormholes would not be shortcuts, on the contrary – News of April 30, 2019 – In 1915, Albert Einstein presented his theory of general relativity, a revolutionary description of gravitation. A few weeks later, he received two letters from another German physicist Karl Schwarzschild. These letters contained the first exact solution to the equations of…
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pulsars

All about pulsars and news

The pulsar PSR J0002 + 6216 was ejected at an incredible speed by a supernova – News of April 2, 2019 – Supernovas and pulsars are linked because a supernova can give birth to a pulsar. When some massive stars arrive at the end of their life, their hydrostatic balance is broken. The thermonuclear reactions…
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hypervelocity stars

All about hypervelocity stars (HVS) and news

The speed of the hypervelocity star LAMOST-HVS1 could have a surprising origin – News of March 19, 2019 – The first hypervelocity star was discovered in 2005. These objects are so fast that their speed exceeds the speed of liberation of the galaxy. They travel at velocities that exceed 500 km per second, which means…
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planet x

All about planet X / planet 9 and news

The observation of another planetary system could explain the orbit of a planet X – News of March 12, 2019 – FarFarOut is part of a class of objects named extreme transneptunians objects. Other objects in this category all have a very eccentric orbit. This is why some researchers believe that a massive object has…
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end of the universe

All about the end of the universe and news

Big Crunch, Big RIP, Big Freeze … How will the universe end ? – News of February 10, 2019 – According to the Big RIP model, the accelerated expansion of the universe continually distances large structures and small structures until even subatomic particles are so far apart that none of the fundamental forces can act.…
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blazars

All about the blazars and news

The light emitted by the blazars makes it possible to better know the universe – News of December 11, 2018 – A team of researchers has devised a method to calculate the number of photons that have been produced in the entire observable universe since its creation. When we look at the sky, we can…
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gravitational waves

All about gravitational waves and news

Gravitational waves could carry messages – News of November 4, 2018 – A team of Russian mathematicians has just published a study. According to this study, it should be possible to encode a message in gravitational waves. There is, however, a huge gap between theory and practice. Although it is possible to encode information in…
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galaxy clusters

All about clusters of galaxies and news

Can we calculate the mass of a cluster of galaxies ? – News of October 28, 2018 – We could try to represent the mass of a cluster of galaxies with respect to the mass of the Milky Way. But the problem is that we do not really know the mass of the Milky Way.…
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