Astronomers find 72 bright and fast explosions

April 2, 2018, Royal Astronomical Society
Images of one of the transient events, from eight days before the maximum brightness to 18 days afterwards. This outburst took place at a distance of 4 billion light years. M. Pursiainen / University of Southampton and DES collaboration

Gone in a (cosmological) flash: a team of astronomers found 72 very bright, but quick events in a recent survey and are still struggling to explain their origin. Miika Pursiainen of the University of Southampton will present the new results on Tuesday 3 April at the European Week of Astronomy and Space Science.

The scientists found the transients in data from the Dark Energy Survey Supernova Programme (DES-SN). This is part of a global effort to understand dark energy, a component driving an acceleration in the expansion of the Universe. DES-SN uses a large camera on a 4-metre telescope in the Cerro Tololo Inter-American Observatory (CTIO) in the Chilean Andes. The survey looks for supernovae, the explosion of massive at the end of their lives. A supernova explosion can briefly be as bright as a whole galaxy, made up of hundreds of billions of stars.

Pursiainen and his collaborators found the largest number of these quick events to date. Even for transient phenomena, they are very peculiar: while they have a similar maximum brightness to different types of supernovae they are visible for less time, from a week to a month. In contrast supernovae last for several months or more.

The events appear to be both hot, with temperatures from 10,000 to 30,000 degrees Celsius, and large ranging in size from several up to a hundred times the distance from Earth to Sun (the Earth is 150 million kilometres from the Sun). They also seem to be expanding and cooling as they evolve in time, as would be expected from an exploding event such as a supernova.

Graph showing the evolution of brightness for two quick transient events and two typical supernovae: thermonuclear and core-collapse. In thermonuclear supernovae an Earth-sized remnant (a white dwarf) of a small sun-like star accretes a critical mass of material from a companion star and explodes. In a core-collapse supernova a massive star exhausts the fuel in its core which causes the core to collapse, triggering an explosion. M. Pursiainen / University of Southampton and DES collaboration

There is still debate on the origin of these transients. One possible scenario is that the star sheds a lot of material before a , and in extreme cases could be completely enveloped by a shroud of matter. The supernova itself may then heat the surrounding material to very high temperatures. In this case astronomers see the hot cloud rather than the exploding star itself. To confirm any of this, the team will need a lot more data.

Pursiainen comments: "The DES-SN survey is there to help us understand , itself entirely unexplained. That then also reveals many more unexplained transients than seen before. If nothing else, our work confirms that astrophysics and cosmology are still sciences with a lot of unanswered questions!"

For the future, the team plan to continue their search for transients, and estimate how often they take place compared with more 'routine' .

Explore further: Astronomers reveal secrets of most distant supernova ever detected

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13 comments

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cantdrive85
1 / 5 (5) Apr 02, 2018
Cosmic lightning!
jonesdave
3.7 / 5 (6) Apr 02, 2018
Cosmic lightning!


Yep, lightning in a conducting medium. Definitely (smh!).
cantdrive85
1 / 5 (4) Apr 03, 2018
Cosmic lightning!


Yep, lightning in a conducting medium. Definitely (smh!).

You clearly know nothing about plasmas, do you?
jonesdave
3.4 / 5 (5) Apr 03, 2018
Cosmic lightning!


Yep, lightning in a conducting medium. Definitely (smh!).

You clearly know nothing about plasmas, do you?


Yep. I know what a collisionless plasma is, which is more than you do. I also know that an electric field will move ions and electrons in opposite directions, which is more than Don Scott knows. Either that or he doesn't understand what the solar wind is composed of.
And I know that lightning needs the breakdown of a dielectric medium. Plasma is a conducting medium, so it ain't happening.
cantdrive85
1 / 5 (2) Apr 03, 2018
And I know that lightning needs the breakdown of a dielectric medium. Plasma is a conducting medium, so it ain't happening.

Like I said, nothing! ROTFLMAO!
alexander2468
3 / 5 (2) Apr 03, 2018
Puzzling conundrums -- electric fields move ions and electrons in opposite directions, +fields repels +ions and attracts -electrons and +ions attracts -electrons so what is the +field attracting or repelling?
jonesdave
3 / 5 (4) Apr 03, 2018
And I know that lightning needs the breakdown of a dielectric medium. Plasma is a conducting medium, so it ain't happening.

Like I said, nothing! ROTFLMAO!


So show us some cosmic lightning woo boy.
jonesdave
4 / 5 (4) Apr 03, 2018
Puzzling conundrums -- electric fields move ions and electrons in opposite directions, +fields repels +ions and attracts -electrons and +ions attracts -electrons so what is the +field attracting or repelling?


Not sure what you are getting at here. If you are asking why the electrons aren't attracted by the ions, and therefore travel along with them; in that case, look at things from the point of view of an electron in the solar wind. It has ions ahead and behind, above and below, all attracting it in directions that cancel each other out. It also has other electrons around it, all repelling it in directions that cancel out. Therefore, once an electric force from an electric field is applied, the electrons will feel this force and move in the opposite direction to the ions. Of course, this isn't what is seen in the solar wind - we have equal amounts of electrons and ions moving in the same direction, at the same speed. Ergo, Don Scott hasn't a clue.
alexander2468
3 / 5 (2) Apr 03, 2018
4H combine into He4 that's 2H released, 2gamma-rays ,2neutrinos and 2positrons. Every 2neutrinos and every 2gamma-rays detected = fusion of hydrogen into helium4
Simple's, count neutrinos and matching gamma-rays divide by 2 and there's fusion.
Supernova clouds are hotter than its star, its star's making heavier element than He4
alexander2468
3 / 5 (2) Apr 03, 2018
That explains the conundrum, opposite charges are coexisting as though there separate
electric fields move ions and electrons in opposite directions, +fields repels +ions and attracts -electrons and +ions attracts -electrons so what is the +field attracting or repelling?

Not sure what you are getting at here. If you are asking why the electrons aren't attracted by the ions, and therefore travel along with them; in that case, look at things from the point of view of an electron in the solar wind. It has ions ahead and behind, above and below, all attracting it in directions that cancel each other out. It also has other electrons around it, all repelling it in directions that cancel out. Therefore, once an electric force from an electric field is applied, the electrons will feel this force and move in the opposite direction to the ions. Of course, this isn't what is seen in the solar wind - we have equal amounts of electrons and ions moving in the same direction.

alexander2468
3 / 5 (2) Apr 03, 2018
And in the solar wind there should be no electric current, with apposing electric fields moving in same direction
Puzzling conundrums?


Of course, this isn't what is seen in the solar wind - we have equal amounts of electrons and ions moving in the same direction, at the same speed. Ergo, Don Scott hasn't a clue.

alexander2468
5 / 5 (3) Apr 03, 2018
There could be, electric currents circulate in aluminium in maglev trains, there's articles on "quantum spin in electric currents in semi-conductors" it's just that it's counter intuitive.
granville583762
5 / 5 (2) Apr 04, 2018
Electric currents induced magnetic fields and Lenz's law
Electric fields in solar wind at 300–500 km/s - Solar wind electric fields in the ion cyclotron frequency range http://iopscience...9265/pdf charged particles in the solar wind deflected away from the earth's magneto sphere

There could be, electric currents circulate in aluminium in maglev trains, there's articles on "quantum spin in electric currents in semi-conductors" it's just that it's counter intuitive.

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