Pulsar PSR J1640-4631

The blue dot in this image marks the spot of an energetic pulsar -- the magnetic, spinning core of star that blew up in a supernova explosion. NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, discovered the pulsar by identifying its telltale pulse -- a rotating beam of X-rays, that like a cosmic lighthouse, intersects Earth every 0.2 seconds.

The pulsar, called PSR J1640-4631, lies in our inner Milky Way galaxy about 42,000 light-years away. It was originally identified by as an intense source of gamma rays by the High Energy Stereoscopic System (H.E.S.S.) in Namibia. NuSTAR helped pin down the source of the gamma rays to a pulsar.

The other pink dots in this picture show low-energy X-rays detected by NASA's Chandra X-ray Observatory.

In this image, NuSTAR data is blue and shows high-energy X-rays with 3 to 79 kiloelectron volts; Chandra data is pink and shows X-rays with 0.5 to 10 kiloeletron volts.

Image credit: NASA/JPL-Caltech/SAO

Note: For more information, see Pulse of a Dead Star Powers Intense Gamma Rays.

Supernova Gaia14aaa and Its Host Galaxy

This image shows the supernova named Gaia14aaa as seen on 10 September 2014 with the robotic Liverpool Telescope on La Palma, in the Canary Islands, Spain. This is a Type Ia supernova – the explosion of a white dwarf locked in a binary system with a companion star – and it was discovered in the data collected with ESA’s Gaia satellite on 30 August.

In the left panel, the image from the Liverpool Telescope shows both Gaia14aaa and its host galaxy, named SDSS J132102.26+453223.8, which is about 500 million light-years away. In this image, the supernova is slightly offset from the galaxy’s core.

The central panel shows an image of the same galaxy, taken as part of the Sloan Digital Sky Survey, several years before the explosion of Gaia14aaa could be observed from Earth.

The right panel was obtained by subtracting the second image, which contains the light emitted by the galaxy, from the first one, which depicts both the galaxy and the supernova. The difference between the two images clearly shows the appearance of Gaia14aaa.

Image credit: M. Fraser/S. Hodgkin/L. Wyrzykowski/H. Campbell/N. Blagorodnova/Z. Kostrzewa-Rutkowska/Liverpool Telescope/SDSS

Note: For more information, see Gaia Discovers Its First Supernova.

SNR Puppis A

Puppis A: A supernova remnant located about 7,000 light years from Earth.

The destructive results of a powerful supernova explosion are seen in a delicate tapestry of X-ray light in this new image. The remnant is called Puppis A, which could have been witnessed on Earth about 3,700 years ago and is about 10 light years across. This image is the most complete and detailed X-ray view of Puppis A ever obtained, made by combining a mosaic of different Chandra and XMM-Newton observations. In this image, low-energy X-rays are shown in red, medium-energy X-rays are in green and high energy X-rays are colored blue.

Scale: Image is about 1.5 degrees across (About 180 light years).

Image credit: X-ray: NASA/CXC/IAFE/G.Dubner et al & ESA/XMM-Newton

Note: For more information, see Puppis A: An X-Ray Tapestry.

Evidence for Supernovas Near Earth

Once every 50 years, more or less, a massive star explodes somewhere in the Milky Way. The resulting blast is terrifyingly powerful, pumping out more energy in a split second than the sun emits in a million years. At its peak, a supernova can outshine the entire Milky Way.

It seems obvious that you wouldn't want a supernova exploding near Earth. Yet there is growing evidence that one did—actually, more than one. About 10 million years ago, a nearby cluster of supernovas went off like popcorn. We know because the explosions blew an enormous bubble in the interstellar medium, and we're inside it.

Astronomers call it "the Local Bubble." It is peanut-shaped, about 300 light years long, and filled with almost nothing. Gas inside the bubble is very thin (0.001 atoms per cubic centimeter) and very hot (roughly a million degrees)—a sharp departure from ordinary interstellar material.

The Local Bubble was discovered gradually in the 1970s and 1980s. Optical and radio astronomers looked carefully for interstellar gas in our part of the galaxy, but couldn't find much in Earth's neighborhood. Meanwhile, x-ray astronomers were getting their first look at the sky using sounding rockets and orbiting satellites, which revealed a million-degree x-ray glow coming from all directions. It all added up to Earth being inside a bubble of hot gas blown by exploding stars.

However, not all researchers agreed.

"Within the last decade, some scientists have been challenging the [supernova] interpretation, suggesting that much or all of the soft X-ray diffuse background is instead a result of charge exchange," says F. Scott Porter of the Goddard Space Flight Center.

"Charge exchange": Basically, it happens when the electrically-charged solar wind comes into contact with a neutral gas. The solar wind can steal electrons from the neutral gas, resulting in an X-ray glow that looks a lot like the glow from an old supernova. Charge exchange has been observed many times in comets.

So, is the X-ray glow that fills the sky a sign of peaceful "charge exchange" in the solar system or evidence of terrifying explosions in the distant past?
image

To find out, an international team researchers including Porter and led by physics professor Massimiliano Galeazzi at the University of Miami in Coral Gables, developed an X-ray detector that could distinguish between the two possibilities. The device was named DXL, for Diffuse X-ray emission from the Local Galaxy.

On December 12, 2012, DXL launched from White Sands Missile Range in New Mexico atop a NASA Black Brant IX sounding rocket, reaching a peak altitude of 160 miles and spending five minutes above Earth's atmosphere. That was all the time they needed to measure the amount of "charge exchange" X-rays inside the solar system.

The results, published online in the journal Nature on July 27, indicate that only about 40 percent of the soft X-ray background originates within the solar system. The rest must come from a Local Bubble of hot gas, the relic of ancient supernovas outside the solar system.

Obviously, those supernovas were not close enough to exterminate life on Earth—but they were close enough to wrap our solar system in a bubble of hot gas that persists millions of years later.

"This is a significant discovery,' said Galeazzi. "[It] affects our understanding of the area of the galaxy close to the sun, and can, therefore, be used as a foundation for future models of the galaxy structure."

Galeazzi and collaborators are already planning the next flight of DXL, which will include additional instruments to better characterize the emission. The launch is currently planned for December 2015.


More information:

How did DXL distinguish between X-rays from charge exchange in the solar system vs. X-rays from hot gas in the Local Bubble?

Answer: Basically, there is a stream of interstellar helium atoms that flows through the solar system. You can read about it here. Every year in December, Earth passes through the "helium focusing cone," a region where this neutral helium is concentrated by the gravitational influence of the sun. The researchers figured the helium focusing cone was probably the strongest source of charge exchange x-rays in the solar system. Using the sounding rocket, they measured the X-ray glow of the helium and found that it could not account for all of the X-rays astronomers had been seeing. There must be a Local Bubble of hot gas to account for the difference.

Video credit: NASA; Illustration credit & copyright: Linda Huff (American Scientist), Priscilla Frisch (U. Chicago)

Magnetar 3XMM J185246.6+003317 Below Supernova Remnant Kesteven 79

Massive stars end their life with a bang, exploding as supernovas and releasing massive amounts of energy and matter. What remains of the star is a small and extremely dense remnant: a neutron star or a black hole.

Neutron stars come in several flavors, depending on properties such as their ages, the strength of the magnetic field concealed beneath their surface, or the presence of other stars nearby. Some of the energetic processes taking place around neutron stars can be explored with X-ray telescopes, like ESA's XMM-Newton.

This image depicts two very different neutron stars that were observed in the same patch of the sky with XMM-Newton. The green and pink bubble dominating the image is Kesteven 79, the remnant of a supernova explosion located about 23,000 light-years away from us.

From the properties of the hot gas in Kesteven 79 and from its size, astronomers estimate that it is between 5000 and 7000 years old. Taking account of the time needed for light to travel to Earth, this means that the supernova that created it must have exploded almost 30,000 years ago. The explosion left behind a young neutron star with a weak magnetic field, which can be seen as the blue spot at the center of Kesteven 79.

Beneath it, a blue splotch indicates an entirely different beast: a neutron star boasting an extremely strong magnetic field, known as a magnetar. Astronomers discovered this magnetar, named 3XMM J185246.6+003317, in 2013 by looking at images that had been taken in 2008 and 2009. After the discovery, they looked at previous images of the same patch of the sky, taken before 2008, but did not find any trace of the magnetar. This suggests that the detection corresponded to an outburst of X-rays released by the magnetar, likely caused by a dramatic change in the structure of its magnetic field.

While the neutron star in the supernova remnant is relatively young, the magnetar is likely a million years old; the age difference means that it is very unlikely that the magnetar arose from the explosion that created Kesteven 79, but must have formed much earlier.

This false-color image is a composite of 15 observations performed between 2004 and 2009 with the EPIC MOS camera on board XMM-Newton. The image combines data collected at energies from 0.3 to 1.2 keV (shown in red), 1.2 to 2 keV (shown in green) and 2 to 7 keV (shown in blue).

Image credit: ESA/XMM-Newton/ Ping Zhou, Nanjing University, China

SN 2014J in Messier 82

In January 2014, a supernova was discovered in the nearby galaxy M82. At a distance of about 11.5 million light-years from Earth, SN2014J as it is known, is the closest of its type to be detected in decades.

This composite Hubble image shows the supernova in visible light, obtained on 31 January with Hubble's Wide Field Camera 3, superimposed on a mosaic of the entire galaxy taken in 2006 with Hubble's Advanced Camera for Surveys.

Image credit: NASA/ESA/A. Goobar (Stockholm University)/Hubble Heritage Team (STScI/AURA)

Note: For more information, see INTEGRAL Catches Dead Star Exploding in a Blaze of Glory and Supernova Explosion.

Eta Carinae

Eta Carinae: A double star system that contains one of the largest most massive stars in the Milky Way galaxy.

The Eta Carinae double star system contains one of the biggest and brightest stars in our Galaxy, weighing at least 90 times the mass of the Sun. It is also extremely volatile and is expected to have at least one supernova explosion in the future. Astronomers are using Chandra to learn more about Eta Carinae through the X-rays it generates. This new Chandra image shows Eta Carinae with low energy X-rays in red, medium energy X-rays in green, and high energy X-rays in blue. The Chandra data are helping to reveal, among other things, how the powerful winds from the two stars in this system interact.

Scale: Image is about 2 arcmin across (about 4.6 light years).

Image credit: NASA/CXC/GSFC/K.Hamaguchi, et al.

Note: For more information, see Eta Carinae: Our Neighboring Superstars.

Artist's Conception of a Galactic Core Forming

This illustration reveals the celestial fireworks deep inside the crowded core of a developing galaxy, as seen from a hypothetical planetary system consisting of a bright, white star and single planet. The sky is ablaze with the glow from nebulae, fledgling star clusters, and stars exploding as supernovae. The rapidly forming core may eventually become the heart of a mammoth galaxy similar to one of the giant elliptical galaxies seen today.

Image credit: NASA/Space Telescope Science Institute

Note: For more information, see NASA Telescopes Uncover Early Construction of Giant Galaxy and Witnessing the Early Growth of a Giant - First Ever Sighting of Galaxy Core Formation.

Supernova Remnant Puppis A

The destructive results of a mighty supernova explosion reveal themselves in a delicate blend of infrared and X-ray light, as seen in this image from NASA's Spitzer Space Telescope and Chandra X-Ray Observatory, and the European Space Agency's XMM-Newton.

The bubbly cloud is an irregular shock wave, generated by a supernova that would have been witnessed on Earth 3,700 years ago. The remnant itself, called Puppis A, is around 7,000 light-years away, and the shock wave is about 10 light-years across.

The pastel hues in this image reveal that the infrared and X-ray structures trace each other closely. Warm dust particles are responsible for most of the infrared light wavelengths, assigned red and green colors in this view. Material heated by the supernova's shock wave emits X-rays, which are colored blue. Regions where the infrared and X-ray emissions blend together take on brighter, more pastel tones.

The shock wave appears to light up as it slams into surrounding clouds of dust and gas that fill the interstellar space in this region.

From the infrared glow, astronomers have found a total quantity of dust in the region equal to about a quarter of the mass of our sun. Data collected from Spitzer's infrared spectrograph reveal how the shock wave is breaking apart the fragile dust grains that fill the surrounding space.

Supernova explosions forge the heavy elements that can provide the raw material from which future generations of stars and planets will form. Studying how supernova remnants expand into the galaxy and interact with other material provides critical clues into our own origins.

Infrared data from Spitzer's multiband imaging photometer (MIPS) at wavelengths of 24 and 70 microns are rendered in green and red. X-ray data from XMM-Newton spanning an energy range of 0.3 to 8 kiloelectron volts are shown in blue.

Image credit: NASA/ESA/JPL-Caltech/GSFC/IAFE

Stardust Discovers Potential Interstellar Space Particles

The largest interstellar dust track found in the Stardust aerogel collectors was this 35 micron-long hole produced by a 3 picogram speck of dust that was probably traveling so fast that it vaporized upon impact. The other two likely interstellar dust grains were traveling more slowly and remained intact after a soft landing in the aerogel.

Seven rare, microscopic interstellar dust particles that date to the beginnings of the solar system are among the samples collected by scientists who have been studying the payload from NASA's Stardust spacecraft since its return to Earth in 2006. If confirmed, these particles would be the first samples of contemporary interstellar dust.

A team of scientists has been combing through the spacecraft's aerogel and aluminum foil dust collectors since Stardust returned in 2006.The seven particles probably came from outside our solar system, perhaps created in a supernova explosion millions of years ago and altered by exposure to the extreme space environment. The particles would be the first confirmed samples of contemporary interstellar dust.

The research report appears in the August 15 issue of the journal Science. Twelve other papers about the particles will appear next week in the journal Meteoritics & Planetary Science.

"These are the most challenging objects we will ever have in the lab for study, and it is a triumph that we have made as much progress in their analysis as we have," said Michael Zolensky, curator of the Stardust laboratory at NASA's Johnson Space Center in Houston and coauthor of the Science paper.

Stardust was launched in 1999 and returned to Earth on January 15, 2006, at the Utah Test and Training Range, 80 miles west of Salt Lake City. The Stardust Sample Return Canister was transported to a curatorial facility at Johnson where the Stardust collectors remain preserved and protected for scientific study.

Inside the canister, a tennis racket-like sample collector tray captured the particles in silica aerogel as the spacecraft flew within 149 miles (about 240 kilometers) of a comet in January 2004. An opposite side of the tray holds interstellar dust particles captured by the spacecraft during its seven-year, three-billion-mile journey.

Scientists caution that additional tests must be done before they can say definitively that these are pieces of debris from interstellar space. But if they are, the particles could help explain the origin and evolution of interstellar dust.

The particles are much more diverse in terms of chemical composition and structure than scientists expected. The smaller particles differ greatly from the larger ones and appear to have varying histories. Many of the larger particles have been described as having a fluffy structure, similar to a snowflake.

Two particles, each only about two microns (thousandths of a millimeter) in diameter, were isolated after their tracks were discovered by a group of citizen scientists. These volunteers, who call themselves "Dusters," scanned more than a million images as part of a University of California, Berkeley, citizen-science project, which proved critical to finding these needles in a haystack.

A third track, following the direction of the wind during flight, was left by a particle that apparently was moving so fast -- more than 10 miles per second (15 kilometers per second) -- that it vaporized. Volunteers identified tracks left by another 29 particles that were determined to have been kicked out of the spacecraft into the collectors.

Four of the particles reported in Science were found in aluminum foils between tiles on the collector tray. Although the foils were not originally planned as dust collection surfaces, an international team led by physicist Rhonda Stroud of the Naval Research Laboratory searched the foils and identified four pits lined with material composed of elements that fit the profile of interstellar dust particles.

Three of these four particles, just a few tenths of a micron across, contained sulfur compounds, which some astronomers have argued do not occur in interstellar dust. A preliminary examination team plans to continue analysis of the remaining 95 percent of the foils to possibly find enough particles to understand the variety and origins of interstellar dust.

Supernovas, red giants and other evolved stars produce interstellar dust and generate heavy elements like carbon, nitrogen and oxygen necessary for life. Two particles, dubbed Orion and Hylabrook, will undergo further tests to determine their oxygen isotope quantities, which could provide even stronger evidence for their extrasolar origin.

Scientists at Johnson have scanned half the panels at various depths and turned these scans into movies, which were then posted online, where the Dusters could access the footage to search for particle tracks.

Once several Dusters tag a likely track, Andrew Westphal, lead author of the Science article, and his team verify the identifications. In the one million frames scanned so far, each a half-millimeter square, Dusters have found 69 tracks, while Westphal has found two. Thirty-one of these were extracted along with surrounding aerogel by scientists at Johnson and shipped to UC Berkeley to be analyzed.

Image credit: UC Berkeley/Andrew Westphal

SN 2014J in Messier 82

M82 SN2014J: A supernova in the galaxy M82 about 11.4 million light years from Earth.

New Chandra data gives insight into the explosion that produced SN 2014J, one of the closest supernovas discovered in decades. SN 2014J is a so-called Type Ia supernova, an important class that astronomers use to measure the expansion of the Universe. This image shows M82 in the low, medium, and high-energy X-rays that Chandra can detect in red, green, and blue respectively. The boxes in the bottom of the image show close-up views of the region around the supernova in data taken prior to the explosion (left), as well as data gathered about three weeks after the supernova went off (right). The lack of X-rays detected by Chandra rules out one mechanism that scientists theorized could cause the star to explode.

Scale: Image is 12.75 arcmin across (42,000 light years across)

Image credit: NASA/CXC/SAO/R.Margutti et al

Note: For more information, see M82 SN2014J: NASA's Chandra Observatory Searches for Trigger of Nearby Supernova.

Four Supernova Remnants

In commemoration of the 15th anniversary of NASA's Chandra X-ray Observatory, four newly processed images of supernova remnants dramatically illustrate Chandra's unique ability to explore high-energy processes in the cosmos (see the accompanying press release).

The images of the Tycho and G292.0+1.8 supernova remnants show how Chandra can trace the expanding debris of an exploded star and the associated shock waves that rumble through interstellar space at speeds of millions of miles per hour. The images of the Crab Nebula and 3C58 show how extremely dense, rapidly rotating neutron stars produced when a massive star explodes can create clouds of high-energy particles light years across that glow brightly in X-rays.

Tycho:
More than four centuries after Danish astronomer Tycho Brahe first observed the supernova that bears his name, the supernova remnant it created is now a bright source of X-rays. The supersonic expansion of the exploded star produced a shock wave moving outward into the surrounding interstellar gas, and another, reverse shock wave moving back into the expanding stellar debris. This Chandra image of Tycho reveals the dynamics of the explosion in exquisite detail. The outer shock has produced a rapidly moving shell of extremely high-energy electrons (blue), and the reverse shock has heated the expanding debris to millions of degrees (red and green). There is evidence from the Chandra data that these shock waves may be responsible for some of the cosmic rays - ultra-energetic particles - that pervade the Galaxy and constantly bombard the Earth.

G292.0+1.8:
At a distance of about 20,000 light years, G292.0+1.8 is one of only three supernova remnants in the Milky Way known to contain large amounts of oxygen. These oxygen-rich supernovas are of great interest to astronomers because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people. The X-ray image from Chandra shows a rapidly expanding, intricately structured, debris field that contains, along with oxygen (yellow and orange), other elements such as magnesium (green) and silicon and sulfur (blue) that were forged in the star before it exploded.

The Crab Nebula:
In 1054 AD, Chinese astronomers and others around the world noticed a new bright object in the sky. This “new star” was, in fact, the supernova explosion that created what is now called the Crab Nebula. At the center of the Crab Nebula is an extremely dense, rapidly rotating neutron star left behind by the explosion. The neutron star, also known as a pulsar, is spewing out a blizzard of high-energy particles, producing the expanding X-ray nebula seen by Chandra. In this new image, lower-energy X-rays from Chandra are red, medium energy X-rays are green, and the highest-energy X-rays are blue.

3C58:
3C58 is the remnant of a supernova observed in the year 1181 AD by Chinese and Japanese astronomers. This new Chandra image shows the center of 3C58, which contains a rapidly spinning neutron star surrounded by a thick ring, or torus, of X-ray emission. The pulsar also has produced jets of X-rays blasting away from it to both the left and right, and extending trillions of miles. These jets are responsible for creating the elaborate web of loops and swirls revealed in the X-ray data. These features, similar to those found in the Crab, are evidence that 3C58 and others like it are capable of generating both swarms of high-energy particles and powerful magnetic fields. In this image, low, medium, and high-energy X-rays detected by Chandra are red, green, and blue respectively.

Image credit: NASA/CXC/SAO

Artist’s Impression of Dust Formation Around a Supernova

This artist’s impression shows dust forming in the environment around a supernova explosion. VLT observations have shown that these cosmic dust factories make their grains in a two-stage process, starting soon after the explosion, but continuing long afterwards.

Illustration credit: ESO/M. Kornmesser

Note: For more information, see VLT Clears Up Dusty Mystery.

Molecular Cloud W48

Just as children are sorted into age groups at school, so the seeds of new stars can also be found in ‘classes’ of others of similar ages. This is especially true when the birth of stars in a cloud of gas and dust is triggered by an external event, like the explosion of a nearby supernova.

This image from ESA’s Herschel space observatory shows a sequence of star-forming regions in the molecular cloud W48, some 10,000 light-years away in the constellation Aquila (the Eagle).

The blue, jellyfish-shaped cloud at the lower left is the oldest stellar nursery in the image. Young and massive stars embedded within it have shaped it into a bubble and heated the diffuse gas, making it shine at the longest wavelengths probed by Herschel.

To its right, another glowing cloud conceals clumps that will evolve into massive stars. These clumps, some of which are visible as bright blotches of light, are also lined up by their age: the older ones at the lower-left and the younger ones to the upper-right. The youngest in this sequence is the small cyan lump at the center of the image, harboring the seeds of future massive stars.

Astronomers believe that this sequence of stellar birth is the result of dozens of supernovas that exploded over 10 million years ago in a region called Aquila Supershell, beyond the left edge of this image. Compressing the surrounding material, these supernovas may have initiated a wave of star formation that sparked, one by one, these stellar cribs.

The image is a composite of the wavelengths of 70 microns (blue), 160 microns (green) and 250 microns (red) and spans about one degree on the long side. North is to the upper-left and east is to the lower left. The data were acquired with Herschel’s PACS and SPIRE instruments in September 2010, as part of a larger map of the W48 molecular complex in the HOBYS Key Programme. This was first published in a paper by Q. Nguyen Luong, et al. 2011. A more detailed study of the star-forming regions shown in this image is presented in a paper by K.L.J. Rygl, et al. 2014.

Image credit: ESA/Herschel/PACS/SPIRE/HOBYS Key Programme Consortium

X-Ray Pulsar SXP 1062

Massive stars end their lives with a bang: exploding as spectacular supernovas, they release huge amounts of mass and energy into space. These explosions sweep up any surrounding material, creating bubble remnants that expand into interstellar space. At the heart of bubbles like these are small, dense neutron stars or black holes, the remains of what once shone brightly as a star.

Since supernova-carved bubbles shine for only a few tens of thousands of years before dissolving, it is rare to come across neutron stars or black holes that are still enclosed within their expanding shell. This image captures such an unusual scene, featuring both a strongly magnetized, rotating neutron star – known as a pulsar – and its cosmic cloak, the remains of the explosion that generated it.

This pulsar, named SXP 1062, lies in the outskirts of the Small Magellanic Cloud, one of the satellite galaxies of our Milky Way galaxy. It is an object known as an X-ray pulsar: it hungrily gobbles up material from a nearby companion star and burps off X-rays as it does so. In the future, this scene may become even more dramatic, as SXP 1062 has a massive companion star that has not yet exploded as a supernova.

Most pulsars whirl around incredibly quickly, spinning many times per second. However, by exploring the expanding bubble around this pulsar and estimating its age, astronomers have noticed something intriguing: SXP 1062 seems to be rotating far too slowly for its age. It is actually one of the slowest pulsars known.

While the cause of this weird sluggishness is still a mystery, one explanation may be that the pulsar has an unusually strong magnetic field, which would slow the rotation.

The diffuse blue glow at the center of the bubble in this image represents X-ray emission from both the pulsar and the hot gas that fills the expanding bubble. The other fuzzy blue objects visible in the background are extragalactic X-ray sources.

This image combines X-ray data from ESA’s XMM-Newton (shown in blue) with optical observations from the Cerro Tololo Inter-American Observatory in Chile. The optical data were obtained using two special filters that reveal the glow of oxygen (shown in green) and hydrogen (shown in red). The size of the image is equivalent to a distance of 457 light-years on a side.

This image was first published on ESA’s Science and Technology website in 2011. It is based on data from the paper “Discovery of a Be/X-ray pulsar binary and associated supernova remnant in the Wing of the Small Magellanic Cloud” by V. Hénault-Brunet, et al. 2012.

Image credit: ESA/XMM-Newton/ L. Oskinova/M. Guerrero; CTIO/R. Gruendl/Y.H. Chu

Note: The above image was first published on this blog in December 2011; however, the above text is different and provides additional information.

Supernova Remnant N103B

This infrared image from NASA's Spitzer Space Telescope shows N103B -- all that remains from a supernova that exploded a millennium ago in the Large Magellanic Cloud, a satellite galaxy 160,000 light-years away from our own Milky Way.

Spitzer's instruments pick up infrared light emitted by dust in both the remnant and the surrounding interstellar medium. The infrared light has been translated to colors we see in this image, allowing astronomers to dissect the scene. In this image, dust associated with the remnant appears red, while dust in the ambient background of the galaxy appears yellow and green. Stars in the field appear blue.

By studying the infrared light emitted from this supernova remnant, astronomers have determined that the density of the gas surrounding the supernova is much higher than is typical for a 'Type Ia' supernova, which are those that occur when dead stars called white dwarfs explode. Astronomers believe that this dense material was expelled prior to the supernova explosion, possibly by a companion to the white dwarf -- an aging star that shed the material.

Most Type Ia supernovas do not show evidence for this process occurring, making N103B an example of a rare subclass of Type Ia explosions. In fact, only one other remnant of a Type Ia explosion shows evidence for this: the remnant of Kepler's supernova in our own galaxy, the remains of the explosion of a star witnessed on Earth in 1604 A.D.

The clump of blue stars seen at the lower right is the cluster known as NGC 1850. Also a resident of the Large Magellanic Cloud, this cluster is made up of young stars yet has the appearance of globular clusters in the Milky Way, which are much older.

The red data shows infrared light with wavelengths of 16 and 24 microns, while shorter-wavelength infrared light of 3.6, 4.5, and 8 microns is shown as blue, cyan and green, respectively.

Image credit: NASA/JPL-Caltech/Goddard

Note: For more information, see New Suspect Identified in Supernova Explosion.

Caracalla Supernova in Galactic Cluster MACSJ1720+35

The heart of a vast cluster of galaxies called MACSJ1720+35 is shown in this image, taken in visible and near-infrared light by the NASA/ESA Hubble Space Telescope.

The galaxy cluster is so massive that its gravity distorts, brightens, and magnifies light from more distant objects behind it, an effect called gravitational lensing. In the top right an exploding star, located behind the cluster can just be made out. It is cataloged as SCP/SN-L2 and nicknamed Caracalla.

The supernova is a member of a special class of exploding star called Type Ia, prized by astronomers because it provides a consistent level of peak brightness that makes it reliable for making distance estimates.

Finding a gravitationally lensed Type Ia supernova gives astronomers a unique opportunity to check the optical "prescription" of the foreground lensing cluster. The supernova is one of three exploding stars discovered in the Cluster Lensing And Supernova survey with Hubble (CLASH), and was followed up as part of a Supernova Cosmology Project HST program. CLASH is a Hubble census that probed the distribution of dark matter in 25 galaxy clusters. Dark matter cannot be seen directly but is believed to make up most of the universe's matter.

The image of the galaxy cluster was taken between March and July 2012 by Hubble's Wide Field Camera 3 and Advanced Camera for Surveys.

Image credit: (top) NASA, ESA, S. Perlmutter (UC Berkeley, LBNL), A. Koekemoer (STScI), M. Postman (STScI), A. Riess (STScI/JHU), J. Nordin (LBNL, UC Berkeley), D. Rubin (Florida State), and C. McCully (Rutgers University); (bottom) NASA, ESA, S. Perlmutter (UC Berkeley, LBNL), A. Koekemoer (STScI), M. Postman (STScI), A. Riess (STScI/JHU), J. Nordin (LBNL, UC Berkeley), D. Rubin (Florida State), and C. McCully (Rutgers University)

Note: For more information, see Cosmic Lens MACS J1720+35 Helps Hubble to Find a Distant Supernova.

NGC 1084

In this new Hubble image, we can see an almost face-on view of the galaxy NGC 1084. At first glance, this galaxy is pretty unoriginal. Like the majority of galaxies that we observe it is a spiral galaxy, and, as with about half of all spirals, it has no bar running through its loosely wound arms. However, although it may seem unremarkable on paper, NGC 1084 is actually a near-perfect example of this type of galaxy — and Hubble has a near-perfect view of it.

NGC 1084 has hosted several violent events known as supernovae — explosions that occur when massive stars, many times more massive than the Sun, approach their twilight years. As the fusion processes in their cores run out of fuel and come to an end, these stellar giants collapse, blowing off their outer layers in a violent explosion. Supernovae can often briefly outshine an entire galaxy, before then fading away over several weeks or months. Although directly observing one of these explosions is hard to do, in galaxies like NGC 1084 astronomers can find and study the remnants left behind.

Astronomers have noted five supernova explosions within NGC 1084 over the past half century. These remnants are named after the year in which they took place — 1963P, 1996an, 1998dl, 2009H, and 2012ec.

The most recent explosion, 2012ec, was detected at the end of NGC 1084’s top right arm in August 2012. It is not visible here as these images were taken in 2001, some eleven years before this supernova exploded. Astronomers at Queen's University Belfast have managed to use these "before" images to directly identify the star that exploded. It appears to be a red supergiant some 10 to 20 times more massive than the Sun, and quite similar to the well-known star Betelguese in Orion.

Photo credit: NASA, ESA, and S. Smartt (Queen's University Belfast)

Open Cluster Berkeley 87 and Star-Forming Region ON2

Massive stars are born in tumultuous clouds of gas and dust. They lead a brief but intense life, blowing powerful winds of particles and radiation that strike their surroundings, before their explosive demise as supernovas.

The interplay between massive stars and their environment is revealed in this image of the star-forming region ON2. It combines X-ray coverage from ESA’s XMM-Newton X-ray observatory with an infrared view from NASA’s Spitzer Space Telescope.

This stellar cradle is associated with the open cluster of stars named Berkeley 87, some 4000 light-years from Earth. The cluster is home to over 2000 stars, most of which are low-mass stars like our Sun or smaller, but some – a few dozen – are stellar monsters weighing 10–80 times more.

Two glowing clouds of gas and dust – the raw material from which stars form – dominate the center of the image and are shown in red. Scattered across the image are a multitude of protostars – seeds of future stellar generations; these are shown in green. The bright yellow star in the upper part of the image is BC Cygni, a massive star that has puffed up enormously and will eventually explode as a supernova.

Shown in blue is XMM-Newton’s X-ray view of ON2: it reveals individual sources – young, massive stars as well as protostars – and more diffuse regions of X-rays. Two ‘bubbles’ of X-rays can be seen in the upper and lower clouds, respectively, pink against the red background. These two bubbles conceal the cumulative emissions from many protostars, but also light radiated by very energetic particles – a signature of shockwaves triggered by massive stars and their winds.

The image combines observations performed in the X-ray energy range of 0.25–12 keV (blue) and at infrared wavelengths of 3.6 microns (green) and 8 microns (red). It spans about 15 arcminutes on each side; north is up and east is to the left.

This image was first published in the paper “Hard X-Ray Emission in the Star-Forming Region ON 2: Discovery with XMM-Newton” by Oskinova et al. in April 2010.

Image credit: L.M. Oskinova, R.A. Gruendl, Spitzer Space Telescope, JPL, NASA & ESA

Supernova Remnant DEM L241

DEM L241: A supernova remnant in the Large Magellanic Cloud about 160,000 light years from Earth.

This composite image contains data from Chandra (purple) that provides evidence for the survival of a companion star from the blast of a supernova explosion. Chandra’s X-rays reveal a point-like source in the supernova remnant at the location of a massive star. The data suggest that mass is being pulled away from the massive star towards a neutron star or a black hole companion. If confirmed, this would be only the third binary system containing both a massive star and a neutron star or black hole ever found in the aftermath of a supernova. This supernova remnant is found embedded in clouds of ionized hydrogen, which are shown in optical light (yellow and cyan) from the MCELS survey, along with additional optical data from the DSS (white).

Scale: Image is 24 arcmin across (1100 light years).

Image credit: X-ray: NASA/CXC/SAO/F.Seward et al; Optical: NOAO/CTIO/MCELS, DSS