X-ray Burst May Be the First Sign of a Supernova

GRB 080913, a distant supernova detected by Swift. This image merges the view through Swift’s UltraViolet and Optical Telescope, which shows bright stars, and its X-ray Telescope. Credit: NASA/Swift/Stefan Immler

The first moments of a massive star going supernova may be heralded by a blast of x-rays, detectable by space telescopes like Swift, which could then tell astronomers where to look for the full show in gamma rays and optical wavelengths. These findings come from the University of Leicester in the UK where a research team was surprised by the excess of thermal x-rays detected along with gamma ray bursts associated with supernovae.

“The most massive stars can be tens to a hundred times larger than the Sun,” said Dr. Rhaana Starling of the University of Leicester  Department of Physics and Astronomy. “When one of these giants runs out of hydrogen gas it collapses catastrophically and explodes as a supernova, blowing off its outer layers which enrich the Universe.

“But this is no ordinary supernova; in the explosion narrowly confined streams of material are forced out of the poles of the star at almost the speed of light. These so-called relativistic jets give rise to brief flashes of energetic gamma-radiation called gamma-ray bursts, which are picked up by monitoring instruments in space, that in turn alert astronomers.”

Powerful gamma ray bursts — GRBs — emitted from supernovae can be detected by both ground-based observatories and NASA’s Swift telescope. Within seconds of detecting a burst (hence its name) Swift relays its location to ground stations, allowing both ground-based and space-based telescopes around the world the opportunity to observe the burst’s afterglow.

But the actual moment of the star’s collapse, when its collapsing core reacts with its surface, isn’t observed — it happens too quickly, too suddenly. If these “shock breakouts” are the source of the excess thermal x-rays (a.k.a. black body emission) that have been recently identified in Swift data, some of the galaxy’s most energetic supernovae could be pinpointed and witnessed at a much earlier moment in time — literally within the first seconds of their birth.

“This phenomenon is only seen during the first thousand seconds of an event, and it is challenging to distinguish it from X-ray emission solely from the gamma-ray burst jet,” Dr. Starling said. “That is why astronomers have not routinely observed this before, and only a small subset of the 700+ bursts we detect with Swift show it.”

Read more: Finding the Failed Supernovae

More observations will be needed to determine if the thermal emissions are truly from the initial collapse of stars and not from the GRB jets themselves. Even if the x-rays are determined to be from the jets it will provide valuable insight to the structure of GRBs… “but the strong association with supernovae is tantalizing,” according to Dr. Starling.

Read more on the University of Leicester press release here, and see the team’s paper in the Nov. 28 online issue of the Monthly Notices of the Royal Astronomical Society here (Full PDF on arXiv.org here.)

Inset image: An artist’s rendering of the Swift spacecraft with a gamma-ray burst going off in the background. Credit: Spectrum Astro. Find out more about the Swift telescope’s instruments here.

 

Unraveling the Secrets of Type Ia Supernovae: a New Two-Minute Thesis

The folks over at PHD Comics have put together a new video in their Two-Minute Thesis series, this one featuring Ph.D candidate Or Graur of the University of Tel Aviv and the American Museum of Natural History discussing the secret lives — and deaths — of astronomers’ “standard candles” of universal distance, Type Ia supernovae.

Judging distances across intergalactic space isn’t easy, so in order to figure out how far away galaxies are astronomers have learned to use the light from Type Ia supernovae, which flare up with the brilliance of 5 billion Suns… and rather precisely so.

Type Ia supernovae are thought to be created from a pairing of two stars: one super-dense white dwarf which draws in material from a binary companion until a critical mass — about 40% more mass than the Sun – is reached. The overpacked white dwarf suddenly undergoes a rapid series of thermonuclear reactions and explodes in an incredibly bright outburst of material and energy.

But exactly what sorts of stellar pairs lead to Type Ia supernovae and how frequently they occur aren’t known, and that’s what Ph.D candidate Or Graur is aiming to learn more about.

Read more: A New Species of Type Ia Supernova?

“We don’t really know what kind of star it is that leads to these explosions, which is kind of embarrassing,” says Graur. “The companion star could be a regular star like our Sun, a red giant or supergiant, or another white dwarf.”

Because stars age at certain rates, by looking deeper into space with the Hubble and Subaru telescopes Graur hopes to determine how often and when in the Universe’s history Type Ia supernovae occur, and thus figure out what types of stars are most likely responsible.

“My rate measurements favor a second white dwarf as the binary companion,” Graur says, “but the issue is far from settled.”

Watch the video for the full story, and visit PHD TV and PHD Comics for more great science illustrations.

Video: PHDComics. Animation: Jorge Cham. Series Producer: Meg Rosenburg. Inset image: merging white dwarfs causing a Type Ia supernova. (NASA/CXC/M Weiss)

Rare Supernova Pair are Most Distant Ever

High-resolution simulation of a galaxy hosting a super-luminous supernova and its chaotic environment in the early Universe. Credit: Adrian Malec and Marie Martig (Swinburne University)

Some of the earliest stars were massive and short-lived, destined to end their lives in huge explosions. Astronomers have detected some of the earliest and most distant of these exploding stars, called ‘super-luminous’ supernovae — stellar explosions 10–100 times brighter than other supernova types. The duo sets a record for the most distant supernova yet detected, and offers clues about the very early Universe.

“The light of these supernovae contains detailed information about the infancy of the Universe, at a time when some of the first stars are still condensing out of the hydrogen and helium formed by the Big Bang,” said Dr. Jeffrey Cooke, an astrophysicist from Swinburne University of Technology in Australia, whose team made the discovery.

The team used a combination of data from the Canada-France-Hawaii Telescope and the Keck 1 Telescope, both located in Hawaii.

“The type of supernovae we’ve found are extremely rare,” Cooke said. “In fact, only one has been discovered prior to our work. This particular type of supernova results from the death of a very massive star (about 100 – 250 times the mass of our Sun) and explodes in a completely different way compared to other supernovae. Discovering and studying these events provides us with observational examples to better understand them and the chemicals they eject into the Universe when they die.”

Super-luminous supernovae were discovered only a few years ago, and are rare in the nearby Universe. Their origins are not well understood, but a small subset of them are thought to occur when extremely massive stars, 150 to 250 times more massive than our Sun, undergo a nuclear explosion triggered by the conversion of photons into electron-positron pairs. This process is completely different compared to all other types of supernovae. Such events are expected to have occurred more frequently in the early Universe, when massive stars were more common.

This, and the extreme brightness of these events, encouraged Cooke and colleagues to search for super-luminous supernovae at redshifts, z, greater than 2, when the Universe was less than one-quarter of its present age.

“We used LRIS (Low Resolution Imaging Spectrometer) on Keck I to get the deep spectroscopy to confirm the host redshifts and to search for late-time emission from the supernovae,” Cooke said. “The initial detections were found in the CFHT Legacy Survey Deep fields. The light from the supernovae arrived here on Earth 4 to 6 years ago. To confirm their distances, we need to get a spectrum of their host galaxies which are very faint because of their extreme distance. The large aperture of Keck and the high sensitivity of LRIS made this possible. In addition, some supernovae have bright enough emission features that persist for years after they explode. The deep Keck spectroscopy is able to detect these lines as a further means of confirmation and study.”

Cooke and co-workers searched through a large volume of the Universe at z greater than or equal to 2, and found two super-luminous supernovae, at redshifts of 2.05 and 3.90 — breaking the previous supernova redshift record of 2.36, and implying a production rate of super-luminous supernovae at these redshifts at least 10 times higher than in the nearby Universe. Although the spectra of these two objects make it unlikely that their progenitors were among the first generation of stars, the present results suggest that detection of those stars may not be far from our grasp.

Detecting the first stars allows us much greater understanding of the first stars in the Universe, Cooke said.

“Shortly after the Big Bang, there was only hydrogen and helium in the Universe,” he said. “All the other elements that we see around us today, such as carbon, oxygen, iron, and silicon, were manufactured in the cores of stars or during supernova explosions. The first stars to form after the Big Bang laid the framework for the long process of enriching the Universe that eventually produced the diverse set of galaxies, stars, and planets we see around us today. Our discoveries probe an early time in the Universe that overlaps with the time we expect to see the first stars.”

Sources: Keck Observatory, Nature

Integral: Ten Years Tracking Extreme Radiation Across the Universe

Caption: Artist’s impression of ESA’s orbiting gamma-ray observatory Integral. Image credit: ESA

Integral, ESA’s International Gamma-Ray Astrophysics Laboratory launched ten years ago this week. This is a good time to look back at some of the highlights of the mission’s first decade and forward to its future, to study at the details of the most sensitive, accurate, and advanced gamma-ray observatory ever launched. But the mission has also had some recent exciting research of a supernova remnant.

Integral is a truly international mission with the participation of all member states of ESA and United States, Russia, the Czech Republic, and Poland. It launched from Baikonur, Kazakhstan on October 17th 2002. It was the first space observatory to simultaneously observe objects in gamma rays, X-rays, and visible light. Gamma rays from space can only be detected above Earth’s atmosphere so Integral circles the Earth in a highly elliptical orbit once every three days, spending most of its time at an altitude over 60 000 kilometres – well outside the Earth’s radiation belts, to avoid interference from background radiation effects. It can detect radiation from events far away and from the processes that shape the Universe. Its principal targets are gamma-ray bursts, supernova explosions, and regions in the Universe thought to contain black holes.

5 metres high and more than 4 tonnes in weight Integral has two main parts. The service module is the lower part of the satellite which contains all spacecraft subsystems, required to support the mission: the satellite systems, including solar power generation, power conditioning and control, data handling, telecommunications and thermal, attitude and orbit control. The payload module is mounted on the service module and carries the scientific instruments. It weighs 2 tonnes, making it the heaviest ever placed in orbit by ESA, due to detectors’ large area needed to capture sparse and penetrating gamma rays and to shield the detectors from background radiation in order to make them sensitive. There are two main instruments detecting gamma rays. An imager producing some of the sharpest gamma-ray images and a spectrometer that gauges gamma-ray energies very precisely. Two other instruments, an X-ray monitor and an optical camera, help to identify the gamma-ray sources.

During its extended ten year mission Integral has has charted in extensive detail the central region of our Milky Way, the Galactic Bulge, rich in variable high-energy X-ray and gamma-ray sources. The spacecraft has mapped, for the first time, the entire sky at the specific energy produced by the annihilation of electrons with their positron anti-particles. According to the gamma-ray emission seen by Integral, some 15 million trillion trillion trillion pairs of electrons and positrons are being annihilated every second near the Galactic Centre, that is over six thousand times the luminosity of our Sun.

A black-hole binary, Cygnus X-1, is currently in the process of ripping a companion star to pieces and gorging on its gas. Studying this extremely hot matter just a millisecond before it plunges into the jaws of the black hole, Integral has discovered that some of it might be escaping along structured magnetic field lines. By studying the alignment of the waves of high-energy radiation originating from the Crab Nebula, Integral found that the radiation is strongly aligned with the rotation axis of the pulsar. This implies that a significant fraction of the particles generating the intense radiation must originate from an extremely organised structure very close to the pulsar, perhaps even directly from the powerful jets beaming out from the spinning stellar core.

Just today ESA reported that Integral has made the first direct detection of radioactive titanium associated with supernova remnant 1987A. Supernova 1987A, located in the Large Magellanic Cloud, was close enough to be seen by the naked eye in February 1987, when its light first reached Earth. Supernovae can shine as brightly as entire galaxies for a brief time due to the enormous amount of energy released in the explosion, but after the initial flash has faded, the total luminosity comes from the natural decay of radioactive elements produced in the explosion. The radioactive decay might have been powering the glowing remnant around Supernova 1987A for the last 20 years.

During the peak of the explosion elements from oxygen to calcium were detected, which represent the outer layers of the ejecta. Soon after, signatures of the material from the inner layers could be seen in the radioactive decay of nickel-56 to cobalt-56, and its subsequent decay to iron-56. Now, after more than 1000 hours of observation by Integral, high-energy X-rays from radioactive titanium-44 in supernova remnant 1987A have been detected for the first time. It is estimated that the total mass of titanium-44 produced just after the core collapse of SN1987A’s progenitor star amounted to 0.03% of the mass of our own Sun. This is close to the upper limit of theoretical predictions and nearly twice the amount seen in supernova remnant Cas A, the only other remnant where titanium-44 has been detected. It is thought both Cas A and SN1987A may be exceptional cases

Christoph Winkler, ESA’s Integral Project Scientist says “Future science with Integral might include the characterisation of high-energy radiation from a supernova explosion within our Milky Way, an event that is long overdue.”

Find out more about Integral here
and about Integral’s study of Supernova 1987A here

A New Species of Type Ia Supernova?

Artist’s conception of a binary star system that produces recurrent novae, and ultimately, the supernova PTF 11kx. (Credit: Romano Corradi and the Instituto de Astrofísica de Canarias)

Although they have been used as the “standard candles” of cosmic distance measurement for decades, Type Ia supernovae can result from different kinds of star systems, according to recent observations conducted by the Palomar Transient Factory team at California’s Berkeley Lab.


Judging distances across intergalactic space from here on Earth isn’t easy. Within the Milky Way — and even nearby galaxies — the light emitted by regularly pulsating stars (called Cepheid variables) can be used to determine how far away a region in space is. Outside of our own local group of galaxies, however, individual stars can’t be resolved, and so in order to figure out how far away distant galaxies are astronomers have learned to use the light from much brighter objects: Type Ia supernovae, which can flare up with a brilliance equivalent to 5 billion Suns.

Type Ia supernovae are created from a special pairing of two stars orbiting each other: one super-dense white dwarf drawing material in from a companion until a critical mass — about 40% more massive than the Sun — is reached. The overpacked white dwarf suddenly undergoes a rapid series of thermonuclear reactions, exploding in an incredibly bright outburst of material and energy… a beacon visible across the Universe.

Because the energy and luminance of Type Ia supernovae have been found to be so consistently alike, distance can be gauged by their apparent brightness as seen from Earth. The dimmer one is when observed, the farther away its galaxy is. Based on this seemingly universal similarity it’s been thought that these supernovae must be created under very similar situations… especially since none have been directly observed — until now.

An international team of astronomers working on the Palomar Transient Factory collaborative survey have observed for the first time a Type Ia supernova-creating star pair — called a progenitor system — located in the constellation Lynx. Named PTF 11kx, the system, estimated to be some 600 million light-years away, contains a white dwarf and a red giant star, a coupling that has not been seen in previous (although indirect) observations.

“It’s a total surprise to find that thermonuclear supernovae, which all seem so similar, come from different kinds of stars,” says Andy Howell, a staff scientist at the Las Cumbres Observatory Global Telescope Network (LCOGT) and a co-author on the paper, published in the August 24 issue of Science. “How could these events look so similar, if they had different origins?”

The initial observations of PTF 11kx were made possible by a robotic telescope mounted on the 48-inch Samuel Oschin Telescope at California’s Palomar Observatory as well as a high-speed data pipeline provided by the NSF, NASA and Department of Energy. The supernova was identified on January 16, 2011 and supported by subsequent spectrography data from Lick Observatory, followed up by immediate “emergency” observations with the Keck Telescope in Hawaii.

“We basically called up a fellow UC observer and interrupted their observations in order to get time critical spectra,” said Peter Nugent, a senior scientist at the Lawrence Berkeley National Laboratory and a co-author on the paper.

The Keck observations showed the PTF 11kx post-supernova system to contain slow-moving clouds of gas and dust that couldn’t have come from the recent supernova event. Instead, the clouds — which registered high in calcium in the Lick spectrographic data — must have come from a previous nova event in which the white dwarf briefly ignited and blew off an outer layer of its atmosphere. This expanding cloud was then seen to be slowing down, likely due to the stellar wind from a companion red giant.

(What’s the difference between a nova and a supernova? Read NASA’s STEREO Spots a New Nova)

Eventually the decelerating nova cloud was impacted by the rapidly-moving outburst from the supernova, evidenced by a sudden burst in the calcium signal which had gradually diminished in the two months since the January event. This calcium burst was, in effect, the supernova hitting the nova and causing it to “light up”.

The observations of PTF 11kx show that Type Ia supernova can occur in progenitor systems where the white dwarf has undergone nova eruptions, possibly repeatedly — a scenario that many astronomers had previously thought couldn’t happen. This could even mean that PTF 11kx is an entirely new species of Type Ia supernova, and while previously unseen and rare, not unique.

Which means our cosmic “standard candles” may need to get their wicks trimmed.

“We know that Type 1a supernovae vary slightly from galaxy to galaxy, and we’ve been calibrating for that, but this PTF 11kx observation is providing the first explanation of why this happens,” Nugent said. “This discovery gives us an opportunity to refine and improve the accuracy of our cosmic measurements.”

Source: Berkeley Lab news center

Inset images: PTF 11kx observation (BJ Fulton, Las Cumbres Observatory Global Telescope Network) / The 48-inch Samuel Oschin Telescope dome at Palomar Observatory. Video: Romano Corradi and the Instituto de Astrofísica de Canarias

Pulsar Sets New Speed Record

A pulsar may have been spotted racing through space at over 6 million miles per hour (9.65 million km/h), setting a new speed record for these curious cosmic objects. If observations are what they appear to be, astronomers will have to recalculate the incredible forces created by supernova explosions.

Seen in observations made with 3 different telescopes — NASA’s Chandra X-ray Observatory, ESA’s XMM-Newton, and the Parkes radio telescope in Australia — the x-ray-emitting object IGR J11014-6103 appears to be racing away from the remnants of a supernova in the constellation Carina, 30,000 light-years from Earth.

The comet-shaped object is thought to be a pulsar, the rapidly-spinning, superdense remains of a star. The facts that it’s dim in optical and infrared wavelengths and hasn’t changed in x-ray brightness between XMM-Newton observations in 2003 and Chandra measurements in 2011 support the claim.

IGR J11014’s comet-like shape may be the result of its breakneck speed through space as its pulsar wind nebula gets blown back by the high-energy bow shock created at the forefront of its passage.

Pulsar wind nebulae are the results of charged particles streaming out from the pulsar itself. The particles, traveling at nearly light-speed, are rapidly decelerated by the interstellar medium and create a visible shock wave. In the case of IGR J11014, the pulsar wind is formed into a “tail” by its bow shock — effectively a sonic boom in front of it.

Further observations will be needed to confirm that IGR J11014 is indeed a pulsar, especially considering that actual pulsations have not yet been detected. If it is a pulsar, and is really traveling at the record-breaking speeds it appears to be — between 5.4 and 6.5 million miles per hour, more than 12 times faster than the Sun travels around the center of the galaxy — a new model of supernova explosions may be required.

Read more on the Chandra news release here.

Image: X-ray: NASA/CXC/UC Berkeley/J.Tomsick et al & ESA/XMM-Newton, Optical: DSS; IR: 2MASS/UMass/IPAC-Caltech/NASA/NSF. Video: NASA/CXC/A. Hobart.

Astrophoto: Supernova PTF11kly During and After

It was literally an event of stellar proportions! In August 2011, a new Type Ia supernova was seen in spiral galaxy M101 a.k.a the Pinwheel Galaxy, located 25 million light-years away. Called PTF11kly, the bright supernova was a target for many astrophotographers. But what does it look like now? Here is a side-by-side comparison by Bill Schlosser from Ohio. It shows his image of the supernova on Sept. 26th, 2011 and then more recently, on June 9th, 2012. “The first was taken through my Astro Tech 10″ RC (I have since sold it) and the second through my TEC 140mm APO,” Bill wrote, and it clearly shows the supernova at its height (brightest object in the left picture, in the lower left side of the galaxy) to what it is today — a small blue blob in the right-hand image. Bill is wondering if it is possibly a becoming nebula now?

Great comparison shots! Check out Bill’s Flickr page for more great photos.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

NASA’s STEREO Spots a New Nova

STEREO-B image of Sagittarii 2012 (STEREO/SECCHI/NASA/NRL)


While on duty observing the Sun from its position in solar orbit, NASA’s STEREO-B spacecraft captured the sudden appearance of a distant bright object. This flare-up turned out to be a nova — designated Sagittarii 2012 — the violent expulsion of material and radiation from a re-igniting white dwarf star.

Unlike a supernova, which is the cataclysmic collapse and explosion of a massive star whose core has finally fused its last, a nova is the result of material falling onto the surface of a white dwarf that’s part of a binary pair. The material, typically hydrogen and helium gas, is drawn off the white dwarf’s partner which has expanded into a red giant.

Eventually the white dwarf cannot contain all of the material that it has sucked in from its neighbor… material which has been heated to tremendous temperatures on its surface as it got compressed further and further by the white dwarf’s incredibly strong gravity. Fusion occurs on the dwarf’s outermost layers, blasting its surface out into space in an explosion of light and energy.

This is a nova — so called because, when witnessed in the night sky, one could suddenly appear as a “new star” in the heavens — sometimes even outshining all other visible stars!

An individual nova will soon fade, but a white dwarf can produce many such flares over time. It all depends on how rapidly it’s accreting material (and how much there is available.)

Over the course of 4 days, Sagittarii 2012 reached a magnitude of about 8.5… still too dim to be seen with the unaided eye, but STEREO-B was able to detect it with its SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) instrument, which is sensitive to extreme ultraviolet wavelengths.

The video above was made from images acquired from April 20 – 24, 2012.

It’s not known yet how far away Sagittarii 2012 is but rest assured it poses no threat to Earth. The energy expelled by a nova is nowhere near that of a supernova, and although you wouldn’t want to have a front-row seat to such an event we’re well away from the danger zone.

What this does show is that STEREO-B is not only a super Sun-watching sentinel, but also very good at observing much more distant stars as well!

Thanks to @SungrazerComets for the heads-up on this novel nova!

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An Ultraviolet, Ultraviolent Supernova Shockwave

The Cygnus Loop in Ultraviolet. Captured by Galex. Image credit: NASA
The Cygnus Loop in Ultraviolet. Captured by Galex. Image credit: NASA

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You’re looking at an insanely beautiful image of the Cygnus Loop nebula captured by NASA’s Galaxy Evolution Explorer (GALEX) mission. Furthermore, this isn’t viewed in plain old visible light, this is high-energy ultraviolet light, revealing regions of hot gas remaining after a supernova detonated here 5,000 to 8,000 years ago.

In fact, the original supernova would have been bright enough to be visible with the unaided eye.

The Cygnus Loop Nebula, also known as W78 or Sharpless 103, is a huge emission nebula measuring more than 3° across. There are many smaller features inside the complex, like the Veil Nebula, the Western Veil (the Witch’s Broom), Eastern Veil and Pickering’s Triangle. Many will be familiar to astronomers and astrophotographers as they’re large and faint, and can only really be revealed with long exposure images in various narrowband filters.

Astronomers originally believed it was located about 2,500 light-years away, but according to newer research with the Hubble Space Telescope, they’ve pegged its distance at only 1,470 light-years away; and it now stretches across a distance of 90 light-years.

This extremely close distance is important. There are many supernova remnants like this, scattered across our galaxy, but none are so close, taking up such a vast region of our skies.

This view was captured by NASA’s GALEX mission, which launched in April 2003. Its main purpose was to image hundreds of thousands of galaxies, charting their rates of star formation – the science is best gathered in ultraviolet. Unfortunately, NASA cut off financial support for the mission back in February, 2011, but control might be transferred to the California Institute of Technology.

Original Source: NASA/Galex News Release

Supernova Primo – Out To Far Frontiers

The top image shows part of the Hubble Ultra Deep Field, the region where astronomers were looking for a supernova blast. The white box pinpoints the area where the supernova is later seen. The image combines observations taken in visible and near-infrared light with the Advanced Camera for Surveys and the Wide Field Camera 3. The image at bottom left, taken by the Wide Field Camera 3, is a close-up of the field without the supernova. A new bright object, identified as the supernova, appears in the Wide Field Camera 3 image at bottom right. Credit: NASA, ESA, A. Riess (Space Telescope Science Institute and The Johns Hopkins University), and S. Rodney (The Johns Hopkins University)

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Its nickname is SN Primo and it’s the farthest Type Ia supernova to have its distance spectroscopically confirmed. When the progenitor star exploded some 9 billion years ago, Primo sent its brilliant beacon of light across time and space to be captured by the Hubble Space Telescope. It’s all part and parcel of a three-year project dealing specifically with Type Ia supernovae. By splitting its light into constituent colors, researchers can verify its distance by redshift and help astronomers better understand not only the expanding Universe, but the constraints of dark energy.

“For decades, astronomers have harnessed the power of Hubble to unravel the mysteries of the Universe,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “This new observation builds upon the revolutionary research using Hubble that won astronomers the 2011 Nobel Prize in Physics, while bringing us a step closer to understanding the nature of dark energy which drives the cosmic acceleration.”

Type Ia supernovae are theorized to have originated from white dwarf stars which have collected an excess of material from their companions and exploded. Because of their remote nature, they have been used to measure great distances with acceptable accuracy. Enter the CANDELS+CLASH Supernova Project… a type of census which utilizes the sharpness and versatility of Hubble’s Wide Field Camera 3 (WFC3) to aid astronomers in the search for supernovae in near- infrared light and verify their distance with spectroscopy. CANDELS is the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and CLASH is the Cluster Lensing and Supernova Survey with Hubble.

“In our search for supernovae, we had gone as far as we could go in optical light,” said Adam Riess, the project’s lead investigator, at the Space Telescope Science Institute and The Johns Hopkins University in Baltimore, Md. “But it’s only the beginning of what we can do in infrared light. This discovery demonstrates that we can use the Wide Field Camera 3 to search for supernovae in the distant Universe.”

However, discovering a supernova like Primo just doesn’t happen overnight. It took the research team several months of work and a huge amount of near-infrared images to locate the faint signature. After capturing the elusive target in October 2010, it was time to employ the WFC3’s spectrometer to validate SN Primo’s distance and analyze the spectra for confirmation of a Type Ia supernova event. Once verified, the team continued to image SN Primo for the next eight months – collecting data as it faded away. By engaging the Hubble in this type of census, astronomers hope to further their understanding of how such events are created. If they should discover that Type Ia supernova don’t always appear the same, it may lead to a way of categorizing those changes and aid in measuring dark energy. Riess and two other astronomers shared the 2011 Nobel Prize in Physics for discovering dark energy 13 years ago, using Type Ia supernova to plot the Universe’s expansion rate.

“If we look into the early Universe and measure a drop in the number of supernovae, then it could be that it takes a long time to make a Type Ia supernova,” said team member Steve Rodney of The Johns Hopkins University. “Like corn kernels in a pan waiting for the oil to heat up, the stars haven’t had enough time at that epoch to evolve to the point of explosion. However, if supernovae form very quickly, like microwave popcorn, then they will be immediately visible, and we’ll find many of them, even when the Universe was very young. Each supernova is unique, so it’s possible that there are multiple ways to make a supernova.”

Original Story Source: Hubble Site News Release.