Until then, the Astronomy scientists Never seen more than four. They just got their hands on one fifth of this new class of starbursts that they named “the cow” – understand ” the a cow ». The explosions are noticeable, because they are brighter – and shorter – than those in Classic supernovae. And this – called AT2020mrf – has another peculiarity: it has not been detected in ghost From the visible, but thanks to the effect episodein a X ray.

after data analysisRather, it turned out that the AT2020mrf emits 200 times more X-rays than the AT2018, which is the first explosion of its kind. “the cow” Discovered in 2018. Unheard of. “I re-analyzed several times because I couldn’t believe it”, so that Yuha, Yao, a researcher at Caltech University (US), in a communication.

The ‘active engine’ behind the starburst

Remember that when a huge star Explode, leave behind, either a Black hole be one star Neutrons. The remnants of stars are usually relatively inactive. But according to researchers, the events “the cow” You should hide like a mid-engine Which feeds intense and continuous x-rays. “It probably has something to do with the ancestral star type.”Yuha Yao suggests.

large amount ofenergy Chest and rapid contrast X-ray seen in the AT2020mrf provides evidence Solid that the nature of this mid-engine Maybe A very active black hole. Or a fast-spinning neutron star that astronomers call a magnetic. But to understand why a mid-engine As an activist, it will certainly be necessary for researchers to study further of these eruptions. Because this class of Supernova “the cow” It seems that he wants to become more diverse than astronomers imagined.

Astronomers have discovered a new class of cosmic explosions

In 2018, a flash Very bright, 200 million light-years away from Milky Way baffled astronomers. A fleeting phenomenon that seemed isolated. But researchers have just identified two similar species. Enough to form a new class of cosmic explosions.

Article from Natalie Mayer Posted on 05/28/2020

The story begins in June 2018, when astronomers witnessed an amazing cosmic explosion about 200 million light-years away from the Milky Way. It was called AT2018 and soon it was called “the cow” – “Cow” – this strange transient phenomenon is observed both from Earth and from space. It is much brighter than a supernova. And the curve of light develops differently. mystery.

Since then, astronomers have discovered two similar transient phenomena. The first, also observed in 2018, occurred about 3.4 billion light-years away. called “koala” – and more scientifically, ZTF18abvkwla. susceptible radio It looks as strong as a file Gamma Burst.

The second transient phenomenon similar to “the cow” I was surprised a few years ago, in 2016, at galaxy About 500 million light-years away, researchers call it CSS161010. “It was so unusual that it took us two years to find out”, says Raffaella Margotti, a university researcher northwest, in one statment National Radio Astronomy Observatory (NRAO, USA). I have already pushed into space the amount “unexpected” of gases and particles in more than 55% of light’s speed.

Astronomers know phenomena capable of ejecting matter at speeds close to the speed of light. Gamma ray bursts and neutron star collisions. But still in very small quantities. On the order of one in a million of Collectivethe Soleil . “Here, we’re talking about 1 to 10% of the mass of our Sun”notes Deanne Copejans, a researcher at the university northwest, in one communication. The evidence, according to the researchers, is that we are dealing here with a new class ofcosmic explosions baptized fast blue light passerby (FBOTs) – “transient blue optical phenomenon” To explain the phenomenon’s speed, a few days, and its peak brightness check in the domain wavelengths blue.

End of life stars in dwarf galaxies

Astronomers believe that at the starting point of FBOTs, there is a file A huge star at the end of life. Remember that a supernova explosion in collapse The core produces a spherical wave of matter that propagates through space. If a disk of matter forms around the neutron star or the black hole that was born from the explosion – “Main Ingredient” Propelling narrow jets of material at nearly the speed of light, the researchers say, it may be that these jets are causing what astronomers call wince Gamma. Researchers are talking about this disc and these puffs of matter ” engine “.

And FBOTs seem to have such a ” engine “. But it consists of MaterialThick, the star lost it before it exploded. Maybe because of a girlfriend Binary. Therefore, when the blast wave hits this material, the luminosity of the phenomenon reaches its peak. The same applies to transmission in the radio field.

Astronomers believe that the stars at the origin of this new type of cosmic explosion are different from those that produce gamma-ray bursts. Since the three phenomena of this kind that have been observed so far are localized in galaxies naines They imagine that it is these dwarf galaxies that allow this kind of stellar evolution. The stars are poor in elements other thanhydrogen and theheliumAs found in this type of galaxy, it actually loses less matter during its lifetime. So they are likely to produce more massive explosions when you’re done.

The researchers also warn that this phenomenon may result from stars being torn apart by medium-sized black constellations. To be sure, you will have to keep an eye on a few FBOTs.

This phenomenon will not be so rare. Astronomers believe other FBOTs are lurking in their data. “We were able to identify them as something different, a rather strange supernova, but since we only had low-rate observations and in the field of optics…”Raffaella Margotti says in a university statement northwest. Indeed, the transient aspect of the phenomenon requires high-speed observations that sweep across vast expanses of sky. And if the field of optics can provide information about moving particles “slowly” At about 10,000 km/s it is necessary to use X-rays or radio waves in the hope of forming a more complete picture of these powerful explosions.