The center of this image contains an extraordinary gamma-ray burst (GRB) called GRB 110328A, observed with NASA's Chandra X-ray Observatory. This Chandra observation confirms the association of GRB 110328A with the core of a distant galaxy and shows that it was an exceptionally long lived and luminous event compared to other GRBs. The red cross (roll your mouse over the image above) shows the position of a faint galaxy -- located about 3.8 billion light years from Earth -- observed with NASA's Hubble Space Telescope and the Gemini-North telescope on the ground. Allowing for experimental errors, the position of the galaxy is indistinguishable from that of the X-ray source, showing that the source is located close to the middle of the galaxy. This is consistent with the idea, suggested by some astronomers, that a star was torn apart by a supermassive black hole at the center of the galaxy. This idea differs from the usual interpretation for a GRB, involving the production of a jet when a black hole or neutron star forms after the collapse of a massive star or a merger between two neutron stars. Remarkably, this "tidal disruption" event may have been caught in real time, rather than detected later from analyzing archival observations. However, this X-ray source is about a hundred times brighter than previously observed tidal disruptions. One possible explanation for this very bright radiation is that debris from the disrupted star fell towards the black hole in a disk and the swirling, magnetized matter generated intense electromagnetic fields that created a powerful jet of particles. If this jet is pointed toward Earth it would boost the observed brightness of the source. This scenario has already been suggested by observers to explain the bright and variable X-ray emission observed by NASA's Swift telescope. This observation was part of a so-called target of opportunity, or TOO, led by Andrew Levan from the University of Warwick in the UK. A TOO allows the telescope to react quickly to unpredictable cosmic events, within 24 hours in some situations. Chandra scientists and engineers can decide to alter the scheduled observations and instead point the telescope to another target if the circumstances warrant it. This process was put into place once the discovery of GRB 110328A with Swift was announced on March 28th, 2011. The Chandra team was able to reset the telescope's schedule to observe GRB 110328A early in the morning of Monday, April 4th for a period of just over four hours.
The NASA/ESA Hubble Space Telescope has pinpointed the source of one of the most puzzling blast of high-energy radiation ever observed. It is at the very center of a small, distant galaxy. The galaxy appears as a bright blob at the center of the Hubble picture. Astronomers say it is likely that a supermassive black hole at the core of the galaxy has gravitationally torn apart and swallowed a bypassing star. As the star’s gas falls onto the black hole, X-ray and gamma radiation is ejected along a narrow beam towards Earth. If confirmed, this would be the first time this phenomenon has been observed.
CfA astronomers have found a pair of white dwarf stars orbiting each other once every 39 minutes. In a few million years, they will merge and reignite as a helium-burning star. In this artist's conception, the reborn star is shown with a hypothetical world.
NASA's Spitzer Space Telescope took this image of a baby star sprouting two identical jets (green lines emanating from fuzzy star). The jet on the right had been seen before in visible-light views, but the jet at left -- the identical twin to the first jet -- could only be seen in detail with Spitzer's infrared detectors. This left jet was hidden behind a dark cloud, which Spitzer can see through. The Spitzer image shows that both of the twin jets, in a system called Herbig-Haro 34, are made up of identical knots of gas and dust, ejected one after another from the area around the star. By studying the spacing of these knots, and knowing the speed of the jets from previous studies, astronomers were able to determine that the jet to the right of the star punches its material out 4.5 years later than the counter-jet. The new data also reveal that the area from which the jets originate is contained within a sphere around the star, with a radius of 3 astronomical units. An astronomical unit is the distance between Earth and the sun. Previous studies estimated that the maximum size of this jet-making zone was 10 times larger. The wispy material is gas and dust. Arc-shaped bow shocks can be seen at the ends of the twin jets. The shocks consist of compressed material in front of the jets. The Herbig-Haro 34 jets are located at approximately 1,400 light-years away in the Orion constellation.
Deep in the Chilean Atacama Desert, far from sources of light pollution and other people-related disturbances, there is a tranquil sky like few others on Earth. This is the site for the European Southern Observatory's Very Large Telescope, a scientific machine at the cutting-edge of technology. In this panoramic photograph, the Large and Small Magellanic Clouds  satellite galaxies of our own  glow brightly on the left, while the VLT’s Unit Telescope 1 stands vigil on the right. Appearing to bridge the gap between them is the Milky Way, the plane of our own galaxy. The seemingly countless stars give a sense of the true scale of the cosmos. Every night ESO astronomers rise to the challenge of studying this vista to make sense of the Universe. This awe-inspiring image was taken by ESO Photo Ambassador Yuri Beletsky. Born in Belarus, Yuri now lives in Chile where he works as an astronomer. The dark skies above the Atacama Desert provide him with splendid opportunities to reveal the majesty of our cosmos, which he is keen to share.
The Soyuz TMA-21 launched from the Baikonur Cosmodrome in Kazakhstan on Tuesday, April 5, 2011, carrying Expedition 27 Soyuz Commander Alexander Samokutyaev, NASA Flight Engineer Ron Garan and Russian Flight Engineer Andrey Borisenko to the International Space Station. The Soyuz, which has been dubbed "Gagarin", is launching one week shy of the 50th anniversary of the launch of Yuri Gagarin from the same launch pad in Baikonur on April 12, 1961 to become the first human to fly in space.
A rich collection of colorful astronomical objects is revealed in this picturesque image of the Rho Ophiuchi cloud complex from NASA's Wide-field Infrared Explorer, or WISE. The Rho Ophiuchi cloud (pronounced 'oh-fee-yoo-ki' and named after a bright star in the region) is found rising above the plane of the Milky Way in the night sky, bordering the constellations Ophiuchus and Scorpius. It's one of the nearest star-forming regions to Earth, allowing us to resolve much more detail than in more distant similar regions, like the Orion nebula. The amazing variety of colors seen in this image represents different wavelengths of infrared light. The bright white nebula in the center of the image is glowing due to heating from nearby stars, resulting in what is called an emission nebula. The same is true for most of the multi-hued gas prevalent throughout the entire image, including the bluish, bow-shaped feature near the bottom right. The bright red area in the bottom right is light from the star in the center - Sigma Scorpii - that is reflected off of the dust surrounding it, creating what is called a reflection nebula. And the much darker areas scattered throughout the image are pockets of cool, dense gas that block out the background light, resulting in absorption (or 'dark') nebulae. WISE's longer wavelength detectors can typically see through dark nebulae, but these are exceptionally opaque. The bright pink objects just left of center are young stellar objects (YSOs). These baby stars are just now forming; many of them are still enveloped in their own tiny compact nebulae. In visible light, these YSOs are completely hidden in the dark nebula that surrounds them, which is sometimes referred to as their baby blanket. We can also see some of the oldest stars in our Milky Way galaxy in this image, found in two separate (and much more distant) globular clusters. The first cluster, M80, is on the far right edge of the image towards the top. The second, NGC 6144, is found close to the bottom edge near the center. They both appear as small densely compacted groups of blue stars. Globular clusters such as these typically harbor some of the oldest stars known, some as old as 13 billion years, born soon after the universe formed. There are two other items of interest in this image as well. At the 3 o'clock position, relative to the bright central region, and about two-thirds of the way from the center to the edge, there is a small faint red dot (more visible in the larger downloadable image files). That dot is an entire galaxy far far away known as PGC 090239. And, at the bottom left of the image, there are two lines emerging from the edge. These were not created by foreground satellites; they are diffraction spikes (optical artifacts from the space telescope) from the bright star Antares that is just out of the field of view. The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust.
The NASA/ESA Hubble Space Telescope has captured a planetary nebula with unconventional good looks. Planetary nebulae signal the demise of mid-sized stars (up to about eight times the mass of the Sun); when the star’s hydrogen fuel supply is exhausted, its outer layers expand and cool, creating a cocoon of gas and dust. This gas then glows as it is bathed in the strong ultraviolet radiation from the central star. NGC 5882 is a quite bright, but small, example of a planetary nebula that lies deep in the southern Milky Way in the constellation of Lupus (The Wolf). Planetary nebulae sometimes have a perfectly symmetrical appearance, with gas being bellowed out from the dying star evenly in every direction. However, this isn’t the case for NGC 5882, as this Hubble image shows. It appears to have two distinct, but non-uniform regions: an elongated inner shell of gas and a fainter aspherical shell that surrounds it. Hubble’s sharp view reveals the intricate knots, filaments and bubbles within these shells. But it’s the dying star at the heart of the planetary nebula that dominates the image, shining brightly with an incredible surface temperature of about 70 000 degrees Celsius. (For comparison, the surface temperature of the Sun is only about 5500 degrees Celsius.) The high surface temperature of this white dwarf is a result of the star’s struggle for survival, finding new ways to prevent itself from collapsing under its own gravity. This picture comes from images taken with Hubble’s Wide Field Planetary Camera 2. Light that comes from glowing ionized oxygen is colored blue (through the F502N filter), yellow/green light (through the broad F555W filter) is shown as green, the light from glowing hydrogen (through the F656N filter) is shown as dark red and light from glowing nitrogen is shown as bright red (through the F658N filter). The exposure times were 320 s, 104 s, 140 s and 1200 s, respectively and the field of view is just 29 arcseconds across.
The wide-angle camera (WAC) is not a typical color camera. It can image in 11 colors, ranging from 430 to 1020 nm wavelength (visible through near-infrared). It does this with a filter wheel: the 11 narrow-band filters (plus one clear filter) are mounted onto a wheel that can be rotated to allow the camera to capture an image through each filter. In this image the 1000 nm, 750 nm, and 430 nm filters are displayed in red, green, and blue, respectively. Several craters appear to have excavated compositionally distinct low-reflectance (brown-blue in this color scheme) material, and the bright rays of Hokusai crater to the north cross the image. During MESSENGER’s orbital operations, we will typically use just eight of the WAC's filters. This decision was made to reduce the amount of data that must be stored on the spacecraft’s solid-state recorder before the information can be downlinked. It’s also quicker than cycling through all 11 filters – the spacecraft is moving rapidly over the surface, and there isn't much time to image the same spot on the surface 11 times over before moving to the next area of interest. The sets of color images will help us learn about the variation in composition from place to place on the planet. For example, some minerals such as olivine and pyroxene often absorb more light at longer wavelengths than at shorter ones, so we’ll be looking for their signatures in the reflectance spectra derived from each eight-color set. WAC images will be used in coordination with the Mercury Atmospheric and Surface Composition Spectrometer (MASCS), a hyperspectral instrument that provides reflectance information at many more wavelengths, but only for one spot on the surface at a time.
Debut double delights Carroll
Linear Mode
