May 23, 2017

Catatumbo Lightning

Catatumbo Lightning

Catatumbo lightning is an atmospheric phenomenon in Venezuela. It occurs only over the mouth of the Catatumbo River where it empties into Lake Maracaibo.

It originates from a mass of storm clouds at a height of more than 1 km, and occurs during 260 nights a year, 10 hours per day and up to 280 times per hour. It occurs over and around Lake Maracaibo, typically over the bog area formed where the Catatumbo River flows into the lake.

Catatumbo lightning changes its frequency throughout the year, and it is different from year to year. For example, it ceased from January to March 2010, apparently due to drought, temporarily raising fears that it might have been extinguished permanently.

Lake Maracaibo, Venezuela
November 1, 2015

Image Credit & Copyright: Fernando Flores
Explanation from: https://en.wikipedia.org/wiki/Catatumbo_lightning

Spiral Galaxy NGC 7714

Spiral Galaxy NGC 7714

NGC 7714 is a spiral galaxy 100 million light-years from Earth — a relatively close neighbour in cosmic terms.

The galaxy has witnessed some violent and dramatic events in its recent past. Tell-tale signs of this brutality can be seen in NGC 7714's strangely shaped arms, and in the smoky golden haze that stretches out from the galactic centre — caused by an ongoing merger with its smaller galactic companion NGC 7715, which is out of the frame of this image.

Image Credit: ESA, NASA
Explanation from: https://www.spacetelescope.org/images/heic1503a/

Open Star Cluster NGC 3572

Open Star Cluster NGC 3572

The Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile has captured the best image so far of the star cluster NGC 3572, a gathering of young stars, and its spectacular surroundings. This new image shows how the clouds of gas and dust around the cluster have been sculpted into whimsical bubbles, arcs and the odd features known as elephant trunks by the stellar winds flowing from the bright stars. The brightest of these cluster stars are heavier than the Sun and will end their short lives as supernova explosions.

Image Credit: ESO/G. Beccari
Explanation from: https://www.eso.org/public/images/eso1347a/

Colima Volcano Eruption

Colima Volcano Eruption

Colima, Mexico
2015

Image Credit: Hernando Rivera Cervantes/SWNS

Emission Nebula Sh2-308

Emission Nebula Sh2-308

The NASA/ESA Hubble Space Telescope still has a few tricks up its sleeve in its task of exploring the Universe. For one, it is able to image two adjacent parts of the sky simultaneously. It does this using two different cameras — one camera can be trained on the target object itself, and the other on a nearby patch of sky so that new and potentially interesting regions of the cosmos can be observed at the same time (these latter observations are known as parallel fields).

This image shows part of a bubble-like cloud of gas — a nebula named Sh2-308 — surrounding a massive and violent star named EZ Canis Majoris. It uses observations from Hubble’s Advanced Camera for Surveys, and is the parallel field associated with another view of the nebula produced by Hubble’s Wide Field Camera 3.

EZ Canis Majoris is something known as a Wolf-Rayet star, and is one of the brightest known stars of its kind. Its outer shell of hydrogen gas has been used up, revealing inner layers of heavier elements that burn at ferocious temperatures. The intense radiation pouring out from EZ Canis Majoris forms thick stellar winds that whip up nearby material, sculpting and blowing it outwards.

These processes have moulded the surrounding gas into a vast bubble. A bubble nebula produced by a Wolf-Rayet star is made of ionised hydrogen (HII), which is often found in interstellar space. In this case, it is the outer hydrogen layers of EZ Canis Majoris — the bubble — that are being inflated by the deluge of radiation — the air — coming from the central star. The fringes of these bubbles are nebulous and wispy, as can be seen in this image.

Image Credit: ESA/Hubble & NASA
Explanation from: https://www.spacetelescope.org/images/potw1721a/

Saturn

Saturn

The projection of Saturn's shadow on the rings grows shorter as Saturn's season advances toward northern summer, thanks to the planet's permanent tilt as it orbits the Sun. This will continue until Saturn's solstice in May 2017. At that point in time, the shadow will extend only as far as the innermost A ring, leaving the middle and outer A ring completely free of the planet's shadow.

Over the course of NASA's Cassini mission, the shadow of Saturn first lengthened steadily until equinox in August 2009. Since then, the shadow has been shrinking. These changes can be seen by comparing the shadow in the above view to its appearance as Cassini approached Saturn in 2004, equinox in 2009, and two years ago, in 2015.

This view looks toward the sunlit side of the rings from about 10 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft wide-angle camera on Feb. 3, 2017.

The view was acquired at a distance of approximately 760,000 miles (1.2 million kilometers) from Saturn. Image scale is 46 miles (73 kilometers) per pixel.

Image Credit: NASA/JPL-Caltech/Space Science Institute
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21328

May 21, 2017

Storm seen from plane above Venezuela

Storm seen from plane above Venezuela

Plane above Caracas, Venezuela
Sepember 12, 2015

Image Credit & Copyright: Santiago Borja

Supernova Remnant RCW 86

Supernova Remnant RCW 86

This image combines data from four different space telescopes to create a multi-wavelength view of all that remains of the oldest documented example of a supernova, called RCW 86. The Chinese witnessed the event in 185 A.D., documenting a mysterious "guest star" that remained in the sky for eight months. X-ray images from the European Space Agency's XMM-Newton Observatory and NASA's Chandra X-ray Observatory are combined to form the blue and green colors in the image. The X-rays show the interstellar gas that has been heated to millions of degrees by the passage of the shock wave from the supernova.

Infrared data from NASA's Spitzer Space Telescope, as well as NASA's Wide-Field Infrared Survey Explorer (WISE) are shown in yellow and red, and reveal dust radiating at a temperature of several hundred degrees below zero, warm by comparison to normal dust in our Milky Way galaxy.

By studying the X-ray and infrared data together, astronomers were able to determine that the cause of the explosion witnessed nearly 2,000 years ago was a Type Ia supernova, in which an otherwise-stable white dwarf, or dead star, was pushed beyond the brink of stability when a companion star dumped material onto it. Furthermore, scientists used the data to solve another mystery surrounding the remnant -- how it got to be so large in such a short amount of time. By blowing a wind prior to exploding, the white dwarf was able to clear out a huge "cavity," a region of very low-density surrounding the system. The explosion into this cavity was able to expand much faster than it otherwise would have.

This is the first time that this type of cavity has been seen around a white dwarf system prior to explosion. Scientists say the results may have significant implications for theories of white-dwarf binary systems and Type Ia supernovae.

RCW 86 is approximately 8,000 light-years away. At about 85 light-years in diameter, it occupies a region of the sky in the southern constellation of Circinus that is slightly larger than the full moon.

Image Credit: NASA/JPL-Caltech/B. Williams (NCSU)
Explanation from: http://www.spitzer.caltech.edu/images/4777-sig11-019-All-Eyes-on-Oldest-Recorded-Supernova

Spiral Galaxy NGC 2841

Spiral Galaxy NGC 2841

Star formation is one of the most important processes in shaping the Universe; it plays a pivotal role in the evolution of galaxies and it is also in the earliest stages of star formation that planetary systems first appear.

Yet there is still much that astronomers don’t understand, such as how do the properties of stellar nurseries vary according to the composition and density of gas present, and what triggers star formation in the first place? The driving force behind star formation is particularly unclear for a type of galaxy called a flocculent spiral, such as NGC 2841 shown here, which features short spiral arms rather than prominent and well-defined galactic limbs.

Image Credit: NASA, ESA and the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration
Explanation from: https://www.spacetelescope.org/images/heic1104a/

Lightning seen from plane above Colombia

Lightning seen from plane above Colombia

Plane above Colombia
February 17, 2017

Image Credit & Copyright: Santiago Borja

Star-Forming Region S106

Star-Forming Region S106

This image shows Sh 2-106, or S106 for short. This is a compact star forming region in the constellation Cygnus (The Swan). A newly-formed star called S106 IR is shrouded in dust at the centre of the image, and is responsible for the surrounding gas cloud’s hourglass-like shape and the turbulence visible within. Light from glowing hydrogen is coloured blue in this image.

The image combines observations from the Hubble Space Telescope (in the centre) with images from the National Astronomical Observatory of Japan’s Subaru Telescope to extend the field of view around the edges of the image.

Image Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA) and NAOJ
Explanation from: https://www.spacetelescope.org/images/heic1118b/

Globular Cluster NGC 6388

Globular Cluster NGC 6388

This image from the NASA/ESA Hubble Space Telescope shows NGC 6388, a dynamically middle-aged globular cluster in the Milky Way. While the cluster formed in the distant past (like all globular clusters, it is over ten billion years old), a study of the distribution of bright blue stars within the cluster shows that it has aged at a moderate speed, and its heaviest stars are in the process of migrating to the centre.

A new study using Hubble data has discovered that globular clusters of the same age can have dramatically different distributions of blue straggler stars within them, suggesting that clusters can age at substantially different rates.

Image Credit: NASA, ESA, F. Ferraro (University of Bologna)
Explanation from: https://www.spacetelescope.org/images/heic1221a/

May 20, 2017

Eyjafjallajökull Volcano Eruption

Eyjafjallajökull Volcano Eruption

Suðurland, Iceland

Image Credit: Árni Sæberg

Galaxy Cluster MACS J0717.5+3745

Galaxy Cluster MACS J0717.5+3745

This is a NASA/ESA Hubble Space Telescope image of the galaxy cluster MACS J0717.5+3745. Shown in blue on the image is a map of the dark matter found within the cluster. This cluster was part of a study of 72 galaxy cluster collisions which determined that dark matter interacts with other dark matter even less than previously thought.

Image Credit: NASA, ESA
Explanation from: http://spacetelescope.org/images/heic1506f/

Cassiopeia A

Cassiopeia A

Astronomers using NASA's infrared Spitzer Space Telescope have discovered that an exploded star, named Cassiopeia A, blew up in a somewhat orderly fashion, retaining much of its original onion-like layering.

"Spitzer has essentially found key missing pieces of the Cassiopeia A puzzle," said Jessica Ennis of the University of Minnesota, Minneapolis.

"We've found new bits of the 'onion' layers that had not been seen before," said Dr. Lawrence Rudnick, also of the University of Minnesota, and principal investigator of the research. "This tells us that the star's explosion was not chaotic enough to stir its remains into one big pile of mush."

Cassiopeia A, or Cas A for short, is what is known as a supernova remnant. The original star, about 15 to 20 times more massive than our sun, died in a cataclysmic "supernova" explosion relatively recently in our own Milky Way galaxy. Like all mature massive stars, the Cas A star was once neat and tidy, consisting of concentric shells made up of various elements. The star's outer skin consisted of lighter elements, such as hydrogen; its middle layers were lined with heavier elements like neon; and its core was stacked with the heaviest elements, such as iron.

Until now, scientists were not exactly sure what happened to the Cas A star when it ripped apart. One possibility is that the star exploded in a more or less uniform fashion, flinging its layers out in successive order. If this were the case, then those layers should be preserved in the expanding debris. Previous observations revealed portions of some of these layers, but there were mysterious gaps.

Spitzer was able to solve the riddle. It turns out that parts of the Cas A star had not been shot out as fast as others when the star exploded. Imagine an onion blasting apart with some layered chunks cracking off and zooming away, and other chunks from a different part of the onion shooting off at slightly slower speeds.

"Now we can better reconstruct how the star exploded," said Dr. William Reach of NASA's Spitzer Science Center, Pasadena, Calif. "It seems that most of the star's original layers flew outward in successive order, but at different average speeds depending on where they started."

How did Spitzer find the missing puzzle pieces? As the star's layers whiz outward, they are ramming, one by one, into a shock wave from the explosion and heating up. Material that hit the shock wave sooner has had more time to heat up to temperatures that radiate X-ray and visible light. Material that is just now hitting the shock wave is cooler and glowing with infrared light. Consequently, previous X-ray and visible-light observations identified hot, deep-layer material that had been flung out quickly, but not the cooler missing chunks that lagged behind. Spitzer's infrared detectors were able to find the missing chunks -- gas and dust consisting of the middle-layer elements neon, oxygen and aluminum.

Cassiopeia A is the ideal target for studying the anatomy of a supernova explosion. Because it is young and relatively close to our solar system, it is undergoing its final death throes right in front of the watchful eyes of various telescopes. In a few hundred years or so, Cas A's scattered remains will have completely mixed together, forever erasing important clues about how the star lived and died.

Image Credit: NASA/JPL-Caltech/L. Rudnick (University of Minnesota)
Explanation from: http://www.spitzer.caltech.edu/news/245-ssc2006-19-NASA-s-Spitzer-Peels-Back-Layers-of-Star-s-Explosion

Ara Ararauna

Ara Ararauna

The blue-and-yellow macaw (Ara ararauna), also known as the blue-and-gold macaw, is a large South American parrot with blue top parts and yellow under parts. It is a member of the large group of neotropical parrots known as macaws. It inhabits forest (especially varzea, but also in open sections of terra firme or unflooded forest) and woodland of tropical South America. They are popular in aviculture because of their striking color, ability to talk, ready availability in the marketplace, and close bonding to humans.

These birds can reach a length of 76–86 cm (30–34 in) and weigh 0.900–1.5 kg (2–3 lb), making them some of the larger members of their family. They are vivid in appearance with blue wings and tail, dark-blue chin, golden under parts, and a green forehead. Their beaks are black. The naked face is white, turning pink in excited birds, and lined with small, black feathers. Blue-and-yellow macaws live from 30 to 35 years in the wild.

Little variation in plumage is seen across the range. Some birds have a more orange or "butterscotch" underside color, particularly on the breast. This was often seen in Trinidad birds and others of the Caribbean area. The blue-and-yellow macaw uses its powerful beak for breaking nutshells, and for climbing up and hanging from trees.

This species occurs in Venezuela, Peru, Brazil, Bolivia, and Paraguay. The range extends slightly into Central America, where it is restricted to Panama. The species' range formerly included Trinidad, but it became extinct there by 1970 as a result of human activities. Between 1999 and 2003, wild-caught blue-and-gold macaws were translocated from Guyana to Trinidad, in an attempt to re-establish the species in a protected area around Nariva swamp. A small breeding population descended from introduced birds is found in Puerto Rico, and another has inhabited Miami-Dade County, Florida, since the mid-1980s.

Explanation from: https://en.wikipedia.org/wiki/Blue-and-yellow_macaw

Two Solar Prominences

Two Solar Prominences

At the edge of the Sun, a large prominence and a small prominence began to shift, turn and fall apart in less than one day (May 8-9, 2017). Prominences are notoriously unstable. Competing magnetic forces pulled the plasma back and forth until they dissipated. The images were taken in a wavelength of extreme ultraviolet light.

Image Credit: NASA/GSFC/Solar Dynamics Observatory
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21634

Exoplanet HD 189733b

Exoplanet HD 189733b

This illustration shows HD 189733b, a huge gas giant that orbits very close to its host star HD 189733. The planet's atmosphere is scorching with a temperature of over 1000 degrees Celsius, and it rains glass, sideways, in howling 7000 kilometre-per-hour winds.

At a distance of 63 light-years from us, this turbulent alien world is one of the nearest exoplanets to Earth that can be seen crossing the face of its star. By observing this planet before, during, and after it disappeared behind its host star during orbit, astronomers were able to deduce that HD 189733b is a deep, azure blue — reminiscent of Earth's colour as seen from space.

Image Credit: NASA, ESA, M. Kornmesser
Explanation from: https://www.spacetelescope.org/images/heic1312a/

May 19, 2017

Mount Tavurvur Volcano Eruption

Mount Tavurvur Volcano Eruption

Rabaul, New Britain, Papua New Guinea
August 29, 2014

Image Credit: Oliver Bluett/AFP/Getty Images

Andromeda Galaxy

Andromeda Galaxy

This mosaic of the Andromeda spiral galaxy highlights explosive stars in its interior, and cooler, dusty stars forming in its many rings. The image is a combination of observations from the Herschel Space Observatory taken in infrared light (seen in orange hues), and the XMM-Newton telescope captured in X-rays (seen in blues). NASA plays a role in both of these European Space Agency-led missions.

Herschel provides a detailed look at the cool clouds of star birth that line the galaxy's five concentric rings. Massive young stars are heating blankets of dust that surround them, causing them to glow in the longer-wavelength infrared light, known as far-infrared, that Herschel sees.

In contrast, XMM-Newton is capturing what happens at the end of the lives of massive stars. It shows the high-energy X-rays that come from, among other objects, supernova explosions and massive dead stars rotating around companions. These X-ray sources are clustered in the center of the galaxy, where the most massive stars tend to form.

Andromeda is our Milky Way galaxy's nearest large neighbor. It is located about 2.5 million light-years away and holds up to an estimated trillion stars. Our Milky Way is thought to contain about 200 billion to 400 billion stars.

Image Credit: ESA/Herschel/PACS/SPIRE/J. Fritz, U. Gent; X-ray: ESA/XMM Newton/EPIC/W. Pietsch, MPE
Explanation from: https://www.nasa.gov/mission_pages/herschel/pia13771.html

Eta Carinae Nebula

Eta Carinae Nebula

Eta Carinae is one of the most massive and brightest stars in the Milky Way. Compared to our own Sun, it is about 100 times as massive and a million times as bright. This famed variable hypergiant star (upper center) is surrounded by the Carina Nebula. In this composite image spanning the visible and infrared parts of the spectrum, areas that appear blue are not obscured by dust, while areas that appear red are hidden behind dark clouds of dust in visible light. A study combining X-ray and Infrared observations has revealed a new population of massive stars lurking in regions of the nebula that are highly obscured by dust. Adding these new massive stars to the known massive stars suggests that the Carina Nebula will produce twice as many supernova explosions as previously supposed.

Visible light in the blue part of the spectrum from the Digital Sky Survey is represented as blue, near infrared light with a wavelength of 2.2 microns from the Two Micron All Sky Survey (2MASS) is green, and infrared observations from the Infrared Array Camera on NASA's Spitzer Space telescope at 3.6 microns is red.

Image Credit: NASA/JPL-Caltech/M. Povich (Penn State Univ.)
Explanation from: http://www.spitzer.caltech.edu/images/3599-sig11-006-New-View-of-the-Great-Nebula-in-Carina

May 18, 2017

Puyehue-Cordón Caulle Volcano Eruption

Puyehue-Cordón Caulle Volcano Eruption 

Osorno, Los Lagos, Chile

Image Credit & Copyright: Francisco Negroni

Jupiter's Little Red Spot

Jupiter's Little Red Spot

This view of Jupiter, taken by the JunoCam imager of NASA's Juno spacecraft, highlights Oval BA -- a massive storm known as the Little Red Spot. Despite its unofficial name, the Little Red Spot is about as wide as Earth. The storm reached its current size when three smaller spots collided and merged in the year 2000. The Great Red Spot, which is about twice as wide as the Little Red Spot, may have formed from the same process centuries ago.

Juno acquired this image on February 2, 2017, at 6:13 a.m. PDT (9:13 a.m. EDT), as the spacecraft performed a close flyby of Jupiter. When the image was taken, the spacecraft was about 9,000 miles (14,500 kilometers) from the planet.

Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Bjorn Jonsson
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21391

Star IRAS 13481-6124

Star IRAS 13481-6124

This star-forming region, captured by NASA's Spitzer Space Telescope, is dominated by the bright, young star IRAS 13481-6124 (upper left), which is about twenty times the mass of our Sun and five times its radius, and is surrounded by its pre-natal cocoon. It is the first massive baby star for which astronomers could obtain a detailed look at the dusty disk closely encircling it. The research provides direct evidence that massive stars do form in the same way as their smaller brethren.

From this archival Spitzer image, as well as from observations done with the APEX 12-metre sub-millimetre telescope, astronomers discovered the presence of a jet, hinting at the presence of a disk. This was then confirmed by observations made with the European Southern Observatory Very Large Telescope Interferometer.

This picture was taken with Spitzer's infrared array camera. It is a four-color composite, in which light with a wavelength of 3.6 microns is blue; 4.5-micron light is green; 5.8-micron light is orange; and 8-micron light is red. Dust appears red-orange and most stars are blue, though ones deeply embedded within dust (like IRAS 13481-6124) take on greenish-yellow tints.

Image Credit: ESO/NASA/JPL-Caltech/S. Kraus
Explanation from: http://www.spitzer.caltech.edu/images/3206-sig10-011-A-Massive-Star-and-Its-Cradle

May 17, 2017

Copahue Volcano Eruption

Copahue Volcano Eruption

Caviahue, Neuquen Province, Argentina
December 22, 2012

Image Credit: AFP/Getty Images

Super Star Cluster Westerlund 1

Super Star Cluster Westerlund 1

This new picture from the VLT Survey Telescope (VST) at ESO's Paranal Observatory shows the remarkable super star cluster Westerlund 1. This exceptionally bright cluster lies about 16 000 light-years from Earth in the southern constellation of Ara (The Altar). It contains hundreds of very massive and brilliant stars, all of which are just a few million years old — babies by stellar standards. But our view of this cluster is hampered by gas and dust that prevents most of the visible light from the cluster's stars from getting to Earth.

Now, astronomers studying images of Westerlund 1 from a new survey of the southern skies have spotted something unexpected in this cluster. Around one of the stars — known as W26, a red supergiant and possibly the biggest star known— they have discovered clouds of glowing hydrogen gas, shown as green features in this new image.

Such glowing clouds around massive stars are very rare, and are even rarer around a red supergiant— this is the first ionised nebula discovered around such a star. W26 itself would be too cool to make the gas glow; the astronomers speculate that the source of the ionising radiation may be either hot blue stars elsewhere in the cluster, or possibly a fainter, but much hotter, companion star to W26.

W26 will eventually explode as a supernova. The nebula that surrounds it is very similar to the nebula surrounding SN1987A, the remnants of a star that went supernova in 1987. SN1987A was the closest observed supernova to Earth since 1604, and as such it gave astronomers a chance to explore the properties of these explosions. Studying objects like this new nebula around W26 will help astronomers to understand the mass loss processes around these massive stars, which eventually lead to their explosive demise.

Image Credit: ESO/VPHAS+ Survey/N. Wright
Explanation from: https://www.eso.org/public/images/potw1341a/

The Tarantula Nebula

Tarantula Nebula

This composite of 30 Doradus, aka the Tarantula Nebula, contains data from Chandra (blue), Hubble (green), and Spitzer (red). Located in the Large Magellanic Cloud, the Tarantula Nebula is one of the largest star-forming regions close to the Milky Way. Chandra's X-rays detect gas that has been heated to millions of degrees by stellar winds and supernovas. This high-energy stellar activity creates shock fronts, which are similar to sonic booms. Hubble reveals the light from massive stars at various stages of star birth, while Spitzer shows where the relatively cooler gas and dust lie.

Image Credit: X-ray: NASA/CXC/PSU/L.Townsley et al.; Optical: NASA/STScI; Infrared: NASA/JPL/PSU/L.Townsley et al.
Explanation from: http://www.spitzer.caltech.edu/images/5130-sig12-004-A-New-View-of-the-Tarantula-Nebula

May 16, 2017

Landslides on Ceres

Landslides on CeresLandslides on CeresLandslides on Ceres

NASA's Dawn spacecraft has revealed many landslides on Ceres, which researchers interpret to have been shaped by a significant amount of water ice. A 2017 study in the journal Nature Geoscience classifies three types of these debris flows.

Image 1 shows an example of "Type I" flow features, which are relatively round and large, have thick "toes" at their ends. They look similar to rock glaciers and icy landslides on Earth. Type I landslides are mostly found at high latitudes, which is also where the most ice is thought to reside near Ceres' surface.

Image 2 shows an example of a "Type II" flow feature. Type II features are often thinner and longer than Type I, and are the most common type of landslide on Ceres. They appear more like the avalanches seen on Earth.

Image 3 shows an example of a "Type III" flow feature at Datan Crater. The study authors interpret Ceres' Type III landslides to involve melted ice, although scientists do not know if they actually contain liquid water. The authors think Type III landslides are related to impact craters, and may have formed during impact events into the ice on Ceres. The features resemble fluid material ejected from craters in the icy regions of Mars and Jupiter's moon Ganymede.

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21471

Exoplanet HD 80606b

Exoplanet HD 80606b

The turbulent atmosphere of a hot, gaseous planet known as HD 80606b is shown in this simulation based on data from NASA's Spitzer Space Telescope. The planet spends most of its time far away from its star, but every 111 days, it swings extremely close to the star, experiencing a massive burst of heat. Spitzer measured the whole heating cycle of this planet, determining its coolest (less than 400 degrees Fahrenheit) and hottest (2,000 degrees Fahrenheit) temperatures.

Image Credit: NASA/JPL-CalTech
Explanation from: https://www.nasa.gov/image-feature/jpl/simulated-atmosphere-of-a-hot-gas-giant

Protoplanetary Disk HH 212

Protoplanetary Disk HH 212

This intriguing image may look like a collection of coloured blobs, but it is actually a high-resolution snapshot of a newborn star enshrouded in dust. Just 1300 light-years away in the Orion Nebula, the star, named HH 212, is remarkably young. The average lifespan of such a low-mass star is around 100 billion years, but this star is only 40 000 years old — truly an infant in stellar terms.

In the cores of the vast molecular clouds in star formation regions, an ongoing battle rages; gravity versus the pressure of gas and dust. If gravity wins, it forces the gas and dust to collapse into a hot dense core that eventually ignites — forming a protostar. All the leftover gas and dust form a spinning disc around this baby star, and in many star systems they eventually coalesce to make planets. Such very young protostellar discs have been hard to image because of their relatively small size, but now the exceedingly high resolution of the Atacama Large Millimeter/submillimeter Array (ALMA) makes it possible to understand the intricate details of star and planet formation.

A closer look at HH 212 reveals a prominent, cool, dark dust lane running through the disc, sandwiched between two brighter regions that are heated by the protostar. The result resembles a cosmic “hamburger”. This is the very first time astronomers have spotted such a dust lane in the earliest phases of star formation, and so it may provide clues as to how planetary systems are born.

Image Credit: ALMA (ESO/NAOJ/NRAO)/ Lee et al.
Explanation from: https://www.eso.org/public/images/potw1720a/

May 15, 2017

Volcán de Colima Eruption

Volcán de Colima Eruption

Colima, Mexico
July 12, 2015

Image Credit: Hector Guerrero/Getty Images

Spiral Galaxy NGC 1097

Spiral Galaxy NGC 1097

Two galaxies, about 50 million light-years away, are locked in a galactic embrace — literally. The Seyfert galaxy NGC 1097, in the constellation of Fornax (The Furnace), is seen in this image taken with the VIMOS instrument on ESO’s Very Large Telescope (VLT). A comparatively tiny elliptical companion galaxy, NGC 1097A, is also visible in the top left. There is evidence that NGC 1097 and NGC 1097A have been interacting in the recent past.

Although NGC 1097 seems to be wrapping its companion in its spiral arms, this is no gentle motherly giant. The larger galaxy also has four faint jets — too extended and faint to be seen in this image — that emerge from its centre, forming an X-shaped pattern, and which are the longest visible-wavelength jets of any known galaxy. The jets are thought to be the remnants of a dwarf galaxy that was disrupted and cannibalised by the much larger NGC 1097 up to a few billion years ago.

These unusual jets are not the galaxy’s only intriguing feature. As previously mentioned, NGC 1097 is a Seyfert galaxy, meaning that it contains a supermassive black hole in its centre. However, the core of NGC 1097 is relatively faint, suggesting that the central black hole is not currently swallowing large quantities of gas and stars. Instead, the most striking feature of the galaxy’s centre is the ring of bright knots surrounding the nucleus. These knots are thought to be large bubbles of glowing hydrogen gas about 750–2500 light-years across, ionised by the intense ultraviolet light of young stars, and they indicate that the ring is a site of vigorous star formation

With this distinctive central star-forming ring, and the addition of numerous bluish clusters of hot, young stars dotted through its spiral arms, NGC 1097 makes a stunning visual object.

The data were originally taken in 2004 with the VIMOS instrument on the VLT, and additional colour information from an image taken by amateur astronomer Robert Gendler has been superimposed. The VLT data were taken through three visible-light filters: R (at a wavelength of 652 nanometres, and shown here in red), V (a wavelength of 540 nanometres, shown in green), and B (456 nanometres, shown in blue). The image covers a region of approximately 7.7 x 6.6 arcminutes on the sky.

Image Credit: ESO/R. Gendler
Explanation from: https://www.eso.org/public/images/potw1128a/

The Moon seen by Lunar Reconnaissance Orbiter

The Moon seen by Lunar Reconnaissance Orbiter

Image Credit: NASA/GSFC/Arizona State University

May 13, 2017

Momotombo Volcano Eruption

Momotombo Volcano Eruption

Papalonal, León, Nicaragua
December 2, 2015

Image Credit: Esteban Felix/AP

Supernova SNR B0049-73.6

Supernova SNR B0049-73.6

The details of how massive stars explode remains one of the biggest questions in astrophysics. Located in the neighboring galaxy of the Small Magellanic Cloud, this supernova, SNR B0049-73.6, provides astronomers with another excellent example of such an explosion to study. Chandra observations of the dynamics and composition of the debris from the explosion support the view that the explosion was produced by the collapse of the central core of a star. In this image, X-rays from Chandra (purple) are combined with infrared data from the 2MASS survey (red, green, and blue).

Image Credit: NASA/CXC/Drew Univ/S.Hendrick et al, 2MASS/UMass/IPAC-Caltech/NASA/NSF
Explanation from: https://www.nasa.gov/mission_pages/chandra/multimedia/small-magellanic-cloud-supernova-remnant.html

View towards the Great Attractor

Great Attractor

This image covers a field of 0.5° x 0.5° in the Southern constellation of Norma (The Level) and in the direction of the "Great Attractor". This region is at an angular distance of about 7° from the main plane of the Milky Way, i.e. less than 15 times the width of the image shown. In this colour composite, the foreground stars in the Milky Way mostly appear as whitish spots (the "crosses" around some of the brighter stars are caused by reflections in the telescope optics). Many background galaxies are also seen. They form a huge cluster (ACO 3627) with a number of bright galaxies near the center — they stand out by their larger size and yellowish colour. In order to facilitate transport over the Web, this image has been compressed by a factor of four from its original size (8500 x 8250 pixels).

Five exposures each were made in blue (B-band filter; 5 x 300 sec), red (R-band filter; 5 x 180 sec) and near-infrared (narrow-band filter centered at 816 nm; 5 x 240 sec) light and combined into a false-colour composite by using blue, green, and red colour for the three images, respectively. A logarithmic intensity scale is used to better show the inner as well as the outer regions of the galaxies in this field.

Image Credit: ESO
Explanation from: https://www.eso.org/public/images/eso9954c/

May 12, 2017

Grímsvötn Volcano Eruption

Grímsvötn Volcano Eruption

Grímsvötn, Vatnajökull, Iceland
May 2011

Image Credit & Copyright: Björn Oddsson

Serpens Star-Forming Region

Serpens Star-Forming Region

Infant stars are glowing gloriously in this infrared image of the Serpens star-forming region, captured by NASA's Spitzer Space Telescope.

The reddish-pink dots are baby stars deeply embedded in the cosmic cloud of gas and dust that collapsed to create it. A dusty disk of cosmic debris, or "protoplanetary disk," that may eventually form planets, surrounds the infant stars.

Wisps of green throughout the image indicate the presence of carbon rich molecules called polycyclic aromatic hydrocarbons. On Earth, these molecules can be found on charred barbecue grills and in automobile exhaust. Blue specks sprinkled throughout the image are background stars in our Milky Way galaxy.

The Serpens star-forming region is located approximately 848 light-years away in the Serpens constellation.

The image is a three-channel, false-color composite, where emission at 4.5 microns is blue, emission at 8.0 microns is green, and 24 micron emission is red.

Image Credit: NASA/JPL-Caltech/UT Austin
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA09072

Galaxy Cluster MACS J0152.5-2852

Galaxy Cluster MACS J0152.5-2852

This is a NASA/ESA Hubble Space Telescope image of the galaxy cluster MACS J0152.5-2852. Shown in blue on the image is a map of the dark matter found within the cluster. This cluster was part of a study of 72 galaxy cluster collisions which determined that dark matter interacts with other dark matter even less than previously thought.

Image Credit: NASA, ESA and HST Frontier Fields

Aurora over Snaefellsnes Peninsula

Aurora over Snaefellsnes Peninsula

Kirkjufell, Snæfellsnes, Iceland
March 18, 2015

Image Credit & Copyright: Babak Tafreshi

Spiral Galaxy NGC 6946

Spiral Galaxy NGC 6946

NGC 6946 is a medium-sized, face-on spiral galaxy about 22 million light years away from Earth. In the past century, eight supernovas have been observed to explode in the arms of this galaxy. Chandra observations (purple) have, in fact, revealed three of the oldest supernovas ever detected in X-rays, giving more credence to its nickname of the "Fireworks Galaxy." This composite image also includes optical data from the Gemini Observatory in red, yellow, and cyan.

Image Credit: X-ray: NASA/CXC/MSSL/R.Soria et al, Optical: AURA/Gemini OBs
Explanation from: https://www.nasa.gov/mission_pages/chandra/multimedia/fireworks-galaxy-ngc6946.html

Supermassive Black Hole CXO J101527.2+625911

Supermassive Black Hole CXO J101527.2+625911
Using data from Chandra and other telescopes, astronomers have found a possible "recoiling" black hole. This black hole, which contains about 160 million solar masses, may have formed and then been set in motion by the collision of two smaller black holes (depicted in the artist's illustration). Astronomers found this candidate recoiling black hole after sifting through data of thousands of galaxies. Such moving supermassive black holes are interesting because they may reveal more about the rate and direction of spin for these enigmatic objects before they merge.

  • Supermassive black holes are typically stationary objects located at the centers of most galaxies.
  • Under some circumstances, these black holes that contain millions or even billions of times the mass of the Sun can be set in motion.
  • After searching through Chandra's X-ray and optical data, astronomers found a new candidate of such a "recoiling" black hole.
  • This recoiling black hole candidate is located in an elliptical galaxy about 3.9 billion light years from Earth.

Supermassive holes are generally stationary objects, sitting at the centers of most galaxies. However, using data from NASA's Chandra X-ray Observatory and other telescopes, astronomers recently hunted down what could be a supermassive black hole that may be on the move.

This possible renegade black hole, which contains about 160 million times the mass of our Sun, is located in an elliptical galaxy about 3.9 billion light years from Earth. Astronomers are interested in these moving supermassive black holes because they may reveal more about the properties of these enigmatic objects.

Supermassive Black Hole CXO J101527.2+625911Supermassive Black Hole CXO J101527.2+625911
The left image is from the Hubble data, which shows two bright points near the middle of the galaxy. One of them is located at the center of the galaxy and the other is located about 3,000 light years away from the center. The latter source shows the properties of a growing supermassive black hole and its position matches that of a bright X-ray source detected with Chandra (right image). Using data from the SDSS and the Keck telescope in Hawaii, the team determined that the growing black hole located near, but visibly offset from, the center of the galaxy has a velocity that is different from the galaxy. These properties suggest that this source may be a recoiling supermassive black hole.

This black hole may have "recoiled," in the terminology used by scientists, when two smaller supermassive black holes collided and merged to form an even larger one. At the same time, this collision would have generated gravitational waves that emitted more strongly in one direction than others. This newly formed black hole could have received a kick in the opposite direction of those stronger gravitational waves. This kick would have pushed the black hole out of the galaxy's center, as depicted in the artist's illustration.

The strength of the kick depends on the rate and direction of spin of the two smaller black holes before they merge. Therefore, information about these important but elusive properties can be obtained by studying the speed of recoiling black holes.

Astronomers found this recoiling black hole candidate by sifting through X-ray and optical data for thousands of galaxies. First, they used Chandra observations to select galaxies that contain a bright X-ray source and were observed as part of the Sloan Digital Sky Survey (SDSS). Bright X-ray emission is a common feature of supermassive black holes that are rapidly growing.

Next, the researchers looked to see if Hubble Space Telescope observations of these X-ray bright galaxies revealed two peaks near their center in the optical image. These two peaks might show that a pair of supermassive black holes is present or that a recoiling black hole has moved away from the cluster of stars in the center of the galaxy.

If those criteria were met, then the astronomers examined the SDSS spectra, which show how the amount of optical light varies with wavelength. If the researchers found telltale signatures in the spectra indicative of the presence of a supermassive black hole, they followed up with an even closer examination of those galaxies.

After all of this searching, a good candidate for a recoiling black hole was discovered. The left image in the inset is from the Hubble data, which shows two bright points near the middle of the galaxy. One of them is located at the center of the galaxy and the other is located about 3,000 light years away from the center. The latter source shows the properties of a growing supermassive black hole and its position matches that of a bright X-ray source detected with Chandra (right image in inset). Using data from the SDSS and the Keck telescope in Hawaii, the team determined that the growing black hole located near, but visibly offset from, the center of the galaxy has a velocity that is different from the galaxy. These properties suggest that this source may be a recoiling supermassive black hole.

The host galaxy of the possible recoiling black hole also shows some evidence of disturbance in its outer regions, which is an indication that a merger between two galaxies occurred in the relatively recent past. Since supermassive black hole mergers are thought to occur when their host galaxies merge, this information supports the idea of a recoiling black hole in the system.

Moreover, stars are forming at a high rate in the galaxy, at several hundred times the mass of the Sun per year. This agrees with computer simulations, which predict that star formation rates may be enhanced for merging galaxies particularly those containing recoiling black holes.

Another possible explanation for the data is that two supermassive black holes are located in the center of the galaxy but one of them is not producing detectable radiation because it is growing too slowly. The researchers favor the recoiling black hole explanation, but more data are needed to strengthen their case.

Image Credit: X-ray: NASA/CXC/NRAO/D.-C.Kim; Optical: NASA/STScI; NASA/CXC/M.Weiss
Explanation from: http://chandra.harvard.edu/photo/2017/rsmbh/

May 11, 2017

Mount Sinabung Volcano Eruption

Mount Sinabung Volcano Eruption

Berastagi, Sumatra, Indonesia
October 13, 2014

Image Credit: Ulet Ifansasti/Getty Images

Supernova Remnant 3C 397

Supernova Remnant 3C 397

3C 397 (also known as G41.1-0.3) is a Galactic supernova remnant with an unusual shape. Researchers think its box-like appearance is produced as the heated remains of the exploded star -- detected by Chandra in X-rays (purple) -- runs into cooler gas surrounding it. This composite of the area around 3C 397 also contains infrared emission from Spitzer (yellow) and optical data from the Digitized Sky Survey (red, green, and blue).

Image Credit: NASA/CXC/Univ of Manitoba/S.Safi-Harb et al, DSS, NASA/JPL-Caltech
Explanation from: https://www.nasa.gov/mission_pages/chandra/multimedia/unusual-supernova-remnant.html

Crab Nebula from Five Observatories

Crab NebulaCrab NebulaCrab NebulaCrab NebulaCrab NebulaCrab Nebula

In the summer of the year 1054 AD, Chinese astronomers saw a new "guest star," that appeared six times brighter than Venus. So bright in fact, it could be seen during the daytime for several months.

This "guest star" was forgotten about until 700 years later with the advent of telescopes. Astronomers saw a tentacle-like nebula in the place of the vanished star and called it the Crab Nebula. Today we know it as the expanding gaseous remnant from a star that self-detonated as a supernova, briefly shining as brightly as 400 million suns. The explosion took place 6,500 light-years away. If the blast had instead happened 50 light-years away it would have irradiated Earth, wiping out most life forms.

In the late 1960s astronomers discovered the crushed heart of the doomed star, an ultra-dense neutron star that is a dynamo of intense magnetic field and radiation energizing the nebula. Astronomers therefore need to study the Crab Nebula across a broad range of electromagnetic radiation, from X-rays to radio waves.

This image combines data from five different telescopes: the VLA (radio) in red; Spitzer Space Telescope (infrared) in yellow; Hubble Space Telescope (visible) in green; XMM-Newton (ultraviolet) in blue; and Chandra X-ray Observatory (X-ray) in purple.

Image Credit: NASA, ESA, G. Dubner (IAFE, CONICET-University of Buenos Aires) et al.; A. Loll et al.; T. Temim et al.; F. Seward et al.; VLA/NRAO/AUI/NSF; Chandra/CXC; Spitzer/JPL-Caltech; XMM-Newton/ESA; and Hubble/STScI
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21474