South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, irradiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning over three full moons on the sky. The nebula is also cataloged as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving astronomers might know this cosmic cloud as the Prawn Nebula. The tantalizing color image is a new astronomical composition using data from the European Southern Observatory's wide field OmegaCAM and amateur images made under dark skies on the Canary Island of Tenerife. via NASA http://ift.tt/2gs74oH
суббота, 10 декабря 2016 г.
четверг, 8 декабря 2016 г.
What's happening at the center of elliptical galaxy NGC 4696? There, long tendrils of gas and dust have been imaged in great detail as shown by this recently released image from the Hubble Space Telescope. These filaments appear to connect to the central region of the galaxy, a region thought occupied by a supermassive black hole. Speculation holds that this black hole pumps out energy that heats surrounding gas, pushes out cooler filaments of gas and dust, and shuts down star formation. Balanced by magnetic fields, these filaments then appear to spiral back in toward and eventually circle the central black hole. NGC 4696 is the largest galaxy in the Centaurus Cluster of Galaxies, located about 150 million light years from Earth. The featured image shows a region about 45,000 light years across. via NASA http://ift.tt/2gaBLeE
среда, 7 декабря 2016 г.
Why is there a glowing oval over Jupiter's South Pole? Aurora. Near the closest part of its first pass near Jupiter in August, NASA's robotic spacecraft Juno captured this dramatic infrared image of a bright auroral ring. Auroras are caused by high energy particles from the Sun interacting with a planet's magnetic field, and ovals around magnetic poles are common. Data from Juno are giving preliminary indications that Jupiter's magnetic field and aurorae are unexpectedly powerful and complex. Unfortunately, a computer glitch caused Juno to go into safe mode during its last pass near the Jovian giant in September. That glitch has now been resolved, making Juno ready for its next pass over Jupiter's cloud tops this coming Sunday. via NASA http://ift.tt/2h2oM3h
вторник, 6 декабря 2016 г.
Have you ever watched a lightning storm in awe? Join the crowd. Oddly, nobody knows exactly how lightning is produced. What is known is that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research. Lightning usually takes a jagged course, rapidly heating a thin column of air to about three times the surface temperature of the Sun. The resulting shock wave starts supersonically and decays into the loud sound known as thunder. Lightning bolts are common in clouds during rainstorms, and on average 44 lightning bolts occur on the Earth every second. Pictured, over 60 images were stacked to capture the flow of lightning-producing storm clouds in July over Colorado Springs, Colorado, USA. via NASA http://ift.tt/2ha4WUe
понедельник, 5 декабря 2016 г.
Familiar stars in Orion and constellations across the sky now have official names. Over the past year, the International Astronomical Union, the only body officially tasked with naming stars, approved names already in common use for 227 of the brightest stars, including the most famous stars on the sky Sirius, Polaris, and Betelgeuse. Pictured, the constellation of Orion is shown with several of these now-official star names superposed. Spanning about 30 degrees, this breath-taking vista stretches across the well-known constellation from head to toe (left to right) and beyond. The common names for all three stars in Orion's belt are also now official. At 1,500 light years away, the Great Orion Nebula is the closest large star forming region, here visible just right and below center. Also visible are famous nebulae including the Horsehead Nebula and the Witch Head Nebula. Of course, the Orion Nebula and bright stars are easy to see with the unaided eye, but dust clouds and emission from the extensive interstellar gas in this nebula-rich complex, are too faint and much harder to record. In the featured mosaic of broadband telescopic images, additional image data acquired with a narrow hydrogen alpha filter was used to bring out the pervasive tendrils of energized atomic hydrogen gas like in the arc of the giant Barnard's Loop. via NASA http://ift.tt/2g7BSuF
воскресенье, 4 декабря 2016 г.
This wide, sharp telescopic view reveals galaxies scattered beyond the stars of the Milky Way at the northern boundary of the high-flying constellation Pegasus. Prominent at the upper right is NGC 7331. A mere 50 million light-years away, the large spiral is one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. The disturbed looking group of galaxies at the lower left is well-known as Stephan's Quintet. About 300 million light-years distant, the quintet dramatically illustrates a multiple galaxy collision, its powerful, ongoing interactions posed for a brief cosmic snapshot. On the sky, the quintet and NGC 7331 are separated by about half a degree. via NASA http://ift.tt/2g4uUXq
суббота, 3 декабря 2016 г.
A triple star system is forming, enshrouded within this dusty natal disk some 750 light-years away in the Perseus molecular cloud. Imaged at millimeter wavelengths by the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, the extreme close-up shows two protostars separated by a mere 61 AU (1 AU is the Earth-Sun distance) with a third 183 AU from the central protostar. The ALMA image also reveals a clear spiral structure indicating instability and fragmentation led to the multiple protostellar objects within the disk. Astronomers estimate that the system, cataloged as L1448 IRS3B, is less than 150,000 years old. Captured at an early phase, the starforming scenario is likely not at all uncommon, since almost half of all sun-like stars have at least one companion. via NASA http://ift.tt/2fOoNI1