Tag: supernova

Unprecedented Image Of A Supernova 80 Million Light Years Away Is Captured For The First Time By An Amateur Astronomer

The first burst of light given off by an exploding star has been captured for the first time by an amateur astronomer in Argentina.

Observations of a dying star 80 million light-years away, taken by Víctor Buso, 60, has given scientists their first view of the initial flash given off by a supernova.

To date, no one has been able to capture the ‘first optical light’ from a supernova, since stars explode seemingly at random in the sky, and the burst is fleeting.

Most are only spotted a long time after the initial blast, making Mr Buso’s one-in-ten-million observations ‘unprecedented‘, scientists said.

The new data provide important clues to the physical structure of the star just before its catastrophic demise and to the nature of the explosion itself.

Professional astronomers have long been searching for such an event,” said University of California at Berkeley astronomer Dr Alex Filippenko, who followed up the lucky discovery with scientific observations of the explosion, called SN 2016gkg.




Observations of stars in the first moments they begin exploding provide information that cannot be directly obtained in any other way.”

It’s like winning the cosmic lottery.”

During tests of a new camera, Mr. Buso snapped images through his 16-inch telescope of the galaxy NGC 613, which is 80 million light-years from Earth.

He took a series of short-exposure photographs of the spiral galaxy, accidentally capturing it before and after the supernova’s ‘shock breakout’.

This is when a pressure wave from the star’s exploding core hits and heats gas at the star’s surface to a very high temperature, causing it to flash and rapidly brighten.

Upon examining the images, Mr. Buso, of Rosario, Argentina, noticed a faint point of light quickly brightening near the end of a spiral arm that was visible in his second set of images but not his first.

Astronomer Dr Melina Bersten and her colleagues at the Instituto de Astrofísica de La Plata in Argentina soon learned of the serendipitous discovery.

They realized that Mr. Buso had caught a rare event; part of the first hour after light emerges from a massive exploding star.

She estimated Mr Buso’s chances of such a discovery, his first supernova, at one in 10 million or perhaps even as low as one in 100 million.

Dr Bersten contacted an international group of astronomers to help conduct additional frequent observations of SN 2016gkg.

A series of subsequent studies have revealed more about the type of star that exploded and the nature of the explosion.

Mr. Buso’s discovery, snapped in September 2016, and results of follow-up observations have now been published in the journal Nature.

Buso’s data are exceptional,” Dr. Filippenko added.

This is an outstanding example of a partnership between amateur and professional astronomers.

The astronomer and his colleagues obtained a series of seven spectra, where the light is broken up into its component colors, as in a rainbow.

They used the Shane 3-meter telescope at the University of California’s Lick Observatory near San Jose, California, and the twin 10-meter telescopes of the W. M. Keck Observatory on Maunakea, Hawaii.

This allowed the international team to determine that the explosion was a Type IIb supernova: The explosion of a massive star that had previously lost most of its hydrogen envelope.

Combining the data with theoretical models, the team estimated that the initial mass of the star was about 20 times the mass of our Sun.

They suggest it lost most of its mass to a companion star and slimmed down to about five solar masses prior to exploding.

Further analyses of the signal could provide further information on the star’s structure and uncover more secrets about supernovas.

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Pass it on: Popular Science

Mystery Of The Zombie Star That Won’t Die

A brightly burning ‘zombie‘ supernova that refuses to die has left astronomers baffled.

The star, which lies half a billion light years away, has exploded numerous times since 1954.

This has stumped astronomers as supernovas are generally considered to explode just once and standard theoretical models cannot explain its behaviour.

Researchers at Las Cumbres Observatory in Goleta, California, have been studying the phenomenon, which was first observed in 2014 by the Intermediate Palomar Transient Factory telescope near San Diego.

In January 2015 the event, known as iPTF14hls, was classified as a type II-P supernova, which results from the rapid collapse and violent explosion of a single massive star.




This type of supernova gives off a distinctive flash and tend to stay bright for around 100 days and supernovae lasting more than 130 days are extremely rare.

But iPTF14hls remained bright for almost two years (600 days), with the brightness of the light it emitted varying by up to 50 per cent over this time, as if it were exploding over and over again.

The evolution of the event also seems to be taking place roughly ten times slower than others of its type.

Adding to the puzzle, telescope imagery uncovered by the team suggests explosions may have taken place at the same location in 1954.

Supernovae are known to explode only once, shine for a few months and then fade, but iPTF14hls experienced at least two explosions, 60 years apart.

Writing in an opinion piece for the journal Nature, Stan Woosley, a professor of astronomy at the University of California, Santa Cruz, said of the findings.

As of now, no detailed model has been published that can explain the observed emission and constant temperature of iPTF14hls, let alone the possible eruption 60 years before the supernova.

“A better understanding could provide insight into the evolution of the most massive stars, the production of the brightest supernovae and possibly the birth of black holes that have masses near 40 solar masses, such as those associated with the first direct detection of gravitational waves.”

“For now, the supernova offers astronomers their greatest thrill: something they do not understand.”

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Pass it on: New Scientist

‘The Strangest Supernova We’ve Ever Seen’: A Star That Keeps Exploding — And Surviving!

A supernova signals a star’s death throes. Having exhausted its fuel for nuclear fusion, the star collapses, producing a gigantic explosion of matter and energy that can be seen from 10 billion light-years away.

The supernova shines for a few months, then fades. All that remains after the cosmic light show is either a dense, smoldering core, called a neutron star, or a gaping black hole.

At least, that is what’s supposed to happen.

Some 500 million light-years away, in a galaxy so distant it looks like little more than a smudge, a star exploded five times over the course of nearly two years, spewing the contents of 50 Jupiters and emitting as much energy as 10 quintillion suns.

This isn’t even the first time this star has gone supernova: Astronomers believe this same body was seen exploding 60 years ago.




Somehow, this “zombie” star has managed to survive one of the most powerful, destructive events known to science — multiple times.

It should make us question, researchers wrote Wednesday in the journal Nature, how much we really know about supernovas.

The discovery was made by scientists working on the Intermediate Palomar Transient Factory, which uses a telescope near San Diego to survey the night sky for ephemeral events like supernovas.

Iair Arcavi, an astrophysicist at the University of California at Santa Barbara and Las Cumbres Observatory who worked on the project, was mainly interested in stars in the early stages of explosion.

So, in September 2014, when the survey captured a fading supernova near the constellation Ursa Major, he didn’t give it much thought. The event looked like a garden variety star well on its way toward oblivion.

Five months later, an intern who had been assigned to look over old data asked Arcavi to look at something weird.

The intern pulled up a plot of the supernova’s emissions over the past 137 days — bizarrely, the explosion was getting brighter.

Figuring that this must be a fluke — maybe just a star in our galaxy twinkling weirdly — Arcavi broke the light from the explosion into its component wavelengths. This “spectrum” contained all the signatures of a supernova.

Even stranger, it looked like a nova that was only 30 days old — though the scientists had concrete proof that it had in fact been going on for months.

The event, dubbed iPTF14hls, was put on 24/7 watch.

The eyes of the Las Cumbres Observatory — a robotic network of telescopes positioned all over the world — followed the supernova as it brightened, then faded, then brightened again.

The nova hit five peaks of brightness before finally seeming to dwindle in summer 2016. But at 600 days old, it was already the longest-lived supernova ever observed.

In an analysis for Nature, Stan Woosley of the University of California at Santa Cruz, who was not involved in the research, wrote that a better understanding of iPTF14hls could lead to revelations about the evolution of massive stars.

The emergence of extremely bright supernovas and, maybe, the origins of the kind of black holes we’ve detected with gravitational waves.

For now,” he concluded, “the supernova offers astronomers their greatest thrill: something they do not understand.

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Pass it on: Popular Science