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Explanation: Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding debris cloud known as Cassiopeia A is an example of this final phase of the stellar life cycle. Light from the explosion which created this supernova remnant would have been first seen in planet Earth's sky about 350 years ago, although it took that light about 11,000 years to reach us....

Explanation: An expanse of cosmic dust, stars and nebulae along the plane of our Milky Way galaxy form a beautiful ring in this projected all-sky view. The creative panorama covers the entire galaxy visible from planet Earth, an ambitious 360 degree mosaic that took two years to complete. Northern hemisphere sites in western China and southern hemisphere sites in New Zealand were used to collect the image data. Like a glowing jewel set in the milky ring, the bulge of the galactic center, is at the very top. Bright planet Jupiter is the beacon just above the central bulge and...

Explanation: Interstellar dust clouds and glowing nebulae abound in the fertile constellation of Orion. One of the brightest, M78, is centered in this colorful, wide field view, covering an area north of Orion's belt. At a distance of about 1,500 light-years, the bluish reflection nebula is around 5 light-years across. Its tint is due to dust preferentially reflecting the blue light of hot, young stars. Reflection nebula NGC 2071 is just to the left of M78. Flecks of emission from Herbig-Haro objects, energetic jets from stars in the process of formation, stand out against the dark dust lanes. The exposure...

Explanation: Do magnetic fields always flow along spiral arms? Our face-on view of the Whirlpool Galaxy (M51) allows a spectacularly clear view of the spiral wave pattern in a disk-shaped galaxy. When observed with a radio telescope, the magnetic field appears to trace the arms' curvature. However, with NASA’s flying Stratospheric Observatory for Infrared Astronomy (SOFIA) observatory, the magnetic field at the outer edge of M51's disk appears to weave across the arms instead. Magnetic fields are inferred by grains of dust aligning in one direction and acting like polaroid glasses on infrared light. In the featured image, the field...

A group of galaxies nicknamed the Copeland Septet, in the constellation of Leo. Astronomers using images from Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory have created the largest ever map of the sky, comprising over a billion galaxies. The final data release from the ambitious DESI Legacy Imaging Surveys sets the stage for a ground-breaking 5-year survey with the Dark Energy Spectroscopic Instrument (DESI), which aims to provide new insights into the nature of dark energy. Credit: KPNO/CTIO/NOIRLab/NSF/AURA/Legacy Imaging Survey ----------------------------------------------------------------------------------------------------- Giant Map of the Sky Sets Stage for Ambitious DESI Survey Astronomers using images from Kitt Peak...

A new clue has just been found that could help solve the mystery of a weirdly dimming star. KIC 8462852, also known as Boyajian's Star, seems to have a binary companion that could be contributing to its irregular dips in brightness. If confirmed with more detailed observations, the newly discovered companion star could help astronomers finally solve KIC 8462852's ongoing mystery. The star was discovered in 2015 by astronomer Tabetha Boyajian (hence it was previously Tabby's Star), and since then it has proven to be a real puzzle. It's a yellow-white dwarf star around 1,470 light-years away, and it keeps...

Updated 7:45 p.m. Eastern with details from briefing. WASHINGTON — A static-fire test of the Space Launch System core stage ended early Jan. 16 when a hydraulic system for one its four engines hit an “intentionally conservative” limit during the test. In a Jan. 19 statement, NASA said the hydraulic system for Engine 2 on the core stage “exceeded the pre-set test limits that had been established” for the Green Run test. “As they were programmed to do, the flight computers automatically ended the test.” Later the same day, during a call with reporters, NASA officials said that the hydraulic...

Magazine article, no link. A reconstruction of our Milky Way's history finds that our galaxy has absorbed at least five large satellites. According to research of Diederik Kruijssen, Heidelberg University Germany. History of our most significant mergers with other galaxies is starting with "the Kraken", which collided with our galaxy around 11 billion years ago. The collision with Kraken must truly transformed our Milky Way Galaxy.

Explanation: Why does a cloudy moon sometimes appear colorful? The effect, called a lunar corona, is created by the quantum mechanical diffraction of light around individual, similarly-sized water droplets in an intervening but mostly-transparent cloud. Since light of different colors has different wavelengths, each color diffracts differently. Lunar Coronae are one of the few quantum mechanical color effects that can be easily seen with the unaided eye. Solar coronae are also sometimes evident. The featured composite image was captured a few days before the close Great Conjunction between Saturn and Jupiter last month. In the foreground, the Italian village of...

Astronomers have discovered black widows and redbacks in space. While these cosmic objects don't kill and eat their mates, the stars share their eight-legged counterparts' violent behavior toward companions. In addition to the run-of-the-mill spider stars, the researchers also discovered a bizarre black widow-redback crossbreed. The scientists used the now-destroyed Arecibo telescope in Puerto Rico to discover the weirdo stars. Spider stars are types of millisecond pulsars, or neutron stars that act like precise clocks in the sky, whirling around at least once every 30 milliseconds and flashing like a lighthouse with each rotation. Neutron stars, the tiny, compressed cores...

Explanation: What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could create stabilizing pressure with nuclear fusion. The resulting supernova remnant, nicknamed the Medulla Nebula for its brain-like shape, still glows in visible light by the heat generated by its collision with confining interstellar gas. Why the nebula also glows in X-ray light, though, remains a mystery. One hypothesis holds that an energetic pulsar was co-created that...

Artistic rendition of the exoplanet WASP-107b and its star, WASP-107. Some of the star's light streams through the exoplanet's extended gas layer. Credit: ESA/Hubble, NASA, M. Kornmesser. ======================================================== The core mass of the giant exoplanet WASP-107b is much lower than what was thought necessary to build up the immense gas envelope surrounding giant planets like Jupiter and Saturn, astronomers at Université de Montréal have found. This intriguing discovery by Ph.D. student Caroline Piaulet of UdeM's Institute for Research on Exoplanets (iREx) suggests that gas-giant planets form a lot more easily than previously believed. Piaulet is part of the groundbreaking research...

Explanation: The jets emanating from Centaurus A are over a million light years long. These jets of streaming plasma, expelled by a giant black hole in the center of this spiral galaxy, light up this composite image of Cen A. Exactly how the central black hole expels infalling matter remains unknown. After clearing the galaxy, however, the jets inflate large radio bubbles that likely glow for millions of years. If energized by a passing gas cloud, the radio bubbles can even light up again after billions of years. X-ray light is depicted in the featured composite image in blue, while...

Explanation: This fantastic skyscape lies near the edge of NGC 2174 a star forming region about 6,400 light-years away in the nebula-rich constellation of Orion. It follows mountainous clouds of gas and dust carved by winds and radiation from the region's newborn stars, now found scattered in open star clusters embedded around the center of NGC 2174, off the top of the frame. Though star formation continues within these dusty cosmic clouds they will likely be dispersed by the energetic newborn stars within a few million years. Recorded at infrared wavelengths by the Hubble Space Telescope in 2014, the interstellar...

Explanation: This shadowy landscape of majestic mountains and icy plains stretches toward the horizon on a small, distant world. It was captured from a range of about 18,000 kilometers when New Horizons looked back toward Pluto, 15 minutes after the spacecraft's closest approach on July 14, 2015. The dramatic, low-angle, near-twilight scene follows rugged mountains formally known as Norgay Montes from foreground left, and Hillary Montes along the horizon, giving way to smooth Sputnik Planum at right. Layers of Pluto's tenuous atmosphere are also revealed in the backlit view. With a strangely familiar appearance, the frigid terrain likely includes ices...

Artist's impression of the KOI-5 system. (Caltech/R. Hurt (IPAC)) ------------------------------------------------------------------------------------------ To us humans, a single Sun feels completely normal, but our Solar System is actually a weird outlier. Most stars in the Milky Way galaxy have at least one companion star. Now, in a system 1,800 light-years away, astronomers have finally confirmed a gas giant planet orbiting a star in a triple star system. This system, called KOI-5, is located in the constellation of Cygnus, and the exoplanet therein has been confirmed more than a decade after it was first detected by the Kepler planet-hunting space telescope. In fact, the...

Explanation: Like salsa verde on your favorite burrito, a green aurora slathers up the sky in this 2017 June 25 snapshot from the International Space Station. About 400 kilometers (250 miles) above Earth, the orbiting station is itself within the upper realm of the auroral displays. Aurorae have the signature colors of excited molecules and atoms at the low densities found at extreme altitudes. Emission from atomic oxygen dominates this view. The tantalizing glow is green at lower altitudes, but rarer reddish bands extend above the space station's horizon. The orbital scene was captured while passing over a point south...

Explanation: What are these two giant arches across the sky? Perhaps the more familiar one, on the left, is the central band of our Milky Way Galaxy. This grand disk of stars and nebulas here appears to encircle much of the southern sky. Visible below the stellar arch is the rusty-orange planet Mars and the extended Andromeda galaxy. For a few minutes during this cold arctic night, a second giant arch appeared to the right, encircling part of the northern sky: an aurora. Auroras are much closer than stars as they are composed of glowing air high in Earth's atmosphere....

Note: move your cursor over the photo at the link to see the line diagram of the constellation displayed. Explanation: The night sky is filled with stories. Cultures throughout history have projected some of their most enduring legends onto the stars above. Generations of people see these stellar constellations, hear the associated stories, and pass them down. Featured here is the perhaps unfamiliar constellation of the Old Man, long recognized by the Tupi peoples native to regions of South America now known as Brazil. The Old Man, in more modern vernacular, may be composed of the Hyades star cluster as...

Researchers used the ALMA telescope array in Chile to discover the quasar A quasar is a type of supermassive black hole that is releasing a lot of energy This object was discovered when the universe was just 670 million years old The discovery can help researchers better understand how these objects form Its age and size brings into doubt theories they were formed from collapsed star clusters, with researchers suggesting they instead feast on cold hydrogen gas =========================================================== The most distant supermassive black hole known to science has been detected by astronomers - and it is more than 13 billion...