Shocking discovery explains powerful novae

September 5, 2017 by Layne Cameron , Laura Chomiuk, Michigan State University
Shocking discovery explains powerful novae
Credit: Michigan State University

In a typical year, there are around 50 novae, nuclear explosions on the surface of white dwarf stars, in our galaxy. Some of these explosions are so bright and powerful, they exceed the scale of scientific explanation.

Employing two powerful telescopes, astronomers at Michigan State University have proven a theory that explains these super-luminous novae and other astronomical explosions. The results, published in the current issue of Nature Astronomy, indicate that powerful shockwaves amplify the explosions beyond any traditional scale for .

"Astronomers have long thought the energy from novae was dominated by the white dwarf, controlling how much light and energy are emitted," said Laura Chomiuk, MSU and study co-author. "What we discovered, however, was a completely different source of energy – shockwaves that can dominate the entire explosion."

As the explosion begins, it ejects a cooler, slower wave of gaseous material, relatively speaking. Behind it, though, is a hot, fast wave speeding right behind it. The collision of the two ejections produces a shockwave, which results in a spectacular explosion of heat and light.

"The bigger the shock, the brighter the nova," Chomiuk said. "We believe it's the speed of the second wave that influences the explosion."

This study explains a theory held by Brian Metzger, Columbia University astronomer, who also is a co-author for this paper.

Now that the theory has been proven, astronomers use novae to better understand other super-charged explosions, like those that mark the death of massive stars in galaxies far away.

"Novae are little laboratories in our galactic backyard that we can use to study some of the most luminous explosions in the universe," Chomiuk said. "As future novae happen, we'll be able to observe them to better understand how shocks light up and fuel explosions. We really want to find out how common and energetic shocks are."

The discovery is marked by the researchers' dogged persistence. When novae happen, there's a good chance they're being observed by Ohio State University's All Sky Automated Survey for SuperNovae. ASAS-SN is a suite of robotic telescopes in the northern and southern hemispheres. In fact, ASAS-SN discovered this particular nova featured in this study – ASASSN-16ma.

When ASASSN-16ma was discovered in October 2016, Kwan-Lok Li, MSU astronomer and lead author, and Chomiuk, requested a second telescope – NASA's Fermi Gamma-ray Space Telescope – also observe the and measure the the nova released. Gamma rays are a direct tracer of shockwaves.

Leaving no stone unturned, Chomiuk also alerted the American Association of Variable Star Observers. This international band of professional and amateur astronomers joined in and provided much of the optical data that proved this discovery.

The observations collected from these sources provided data that was unparalleled. The unequivocal results, when expressed through a graph, display a pulsating line of energy – resembling a galactic heartbeat, of sorts – with the optical light and the gamma rays mirroring each other and proving the theory. The gamma rays and the optical light come from the same source – showing that shocks dominate the nova's luminosity.

"The nova's brightness and how strong our data were really surprised me," Li said. "Other may take days or weeks for us to collect sufficient data. This one, though, was visible after just one day, and we knew it was a good one."

Explore further: Fermi satellite detects gamma-rays from exploding novae

More information: Kwan-Lok Li et al. A nova outburst powered by shocks, Nature Astronomy (2017). DOI: 10.1038/s41550-017-0222-1

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14 comments

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MrNewTime
Sep 05, 2017
This comment has been removed by a moderator.
antialias_physorg
5 / 5 (14) Sep 05, 2017
MrNewTime...please take your meds before posting.
You are on a science site. Not on HuffPo.

Thank you.
MrNewTime
1 / 5 (13) Sep 05, 2017
Well, expanding space is naked empire.

Space is eternal and infinity place which is nothing.

"In" space we have a eternal movement = energy = pushing force

Nucleus of atoms expanding and recycling expanding pushing force which have a nature like expanding light, expanding electrons etc.
antialias_physorg
5 / 5 (11) Sep 05, 2017

Well, expanding space is naked empire.

Space is eternal and infinity place which is nothing.

"In" space we have a eternal movement = energy = pushing force

Nucleus of atoms expanding and recycling expanding pushing force which have a nature like expanding light, expanding electrons etc.

None of what you just posted makes any kind of sense.

Note to others, because MrNewTime is such a good example:
You can tell a crazy person/crank right away when they try to pass off a 'scientese' statement by adding "etc."

MrNewTime
1 / 5 (11) Sep 05, 2017
Expanding space is just like god. You can only believe, there is expanding space.

If nucleus of atoms expanding and recycle expanding pushing force, we can proof that science way. Thats because we can make science test with matter. With space you cant. With light you can. So, i have idea which is science.

Expanding space is something like god.
Zzzzzzzz
5 / 5 (7) Sep 05, 2017
Expanding space is just like god. You can only believe, there is expanding space.

If nucleus of atoms expanding and recycle expanding pushing force, we can proof that science way. Thats because we can make science test with matter. With space you cant. With light you can. So, i have idea which is science.

Expanding space is something like god.


Sorry, that is nothing but babble. Onto the ignore list you go.
Whydening Gyre
4 / 5 (4) Sep 05, 2017
Mr. New Times "novel" explanations aside, this article's treatise makes good sense...
bschott
1.8 / 5 (5) Sep 05, 2017
Mr. New Times "novel" explanations aside, this article's treatise makes good sense...

Their explanation doesn't even match the emission profile shown in the graphic.

As the explosion begins, it ejects a cooler, slower wave of gaseous material, relatively speaking. Behind it, though, is a hot, fast wave speeding right behind it. The collision of the two ejections produces a shockwave, which results in a spectacular explosion of heat and light.

NOV 6th...no light...NOV 9th....brightest emission....NOV 12th....dims down....NOV 15th....re-brightening. The material would have to interact twice to produce the observation, they have not suggested this happens. Also curiously absent from the emission spectra are the events that caused both matter expulsions (you can't have this without an energetic output which would also be characterized by brightening).
Perhaps z X 8 has an explanation.....

rrwillsj
5 / 5 (2) Sep 05, 2017
"Now that the theory has been proven,"

Ohh, geewhilickers.... I sure wish the writers of this article had not phrased their conclusion with such an absolutist term.

Cause I get the sneaky feeling that such language will wind up biting them on their respective asses.

No matter how accurate their evidence or how rigid their methodology. This universe does not exist to provide answers. But rather, to provide the opportunity to invent new questions. Many of which will never find a definitive answer.

Editor moderate "Now that the theory has been proven," to "Now that empirical evidence supporting the theory is available? Now the research continues seeking supporting evidence to confirm that this theory is substantially, possibly correct. Or not.
nikola_milovic_378
Sep 06, 2017
This comment has been removed by a moderator.
FineStructureConstant
5 / 5 (10) Sep 06, 2017
@nik
Please disagree, if you can
That would be like trying to disagree with a Jackson Pollock painting. You've thrown gobs of science words onto the page canvas, and they make some kind of a hazy structure - but only you know what the hell it means.
nikola_milovic_378
Sep 06, 2017
This comment has been removed by a moderator.
cantdrive85
1 / 5 (3) Sep 07, 2017
Cosmic ball lightning.
nikola_milovic_378
Sep 08, 2017
This comment has been removed by a moderator.

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