Einstein Rings are more than just an incredible novelty. It’s also a very rare phenomenon that can offer insights into dark matter, dark energy, the nature of distant galaxies, and the curvature of the Universe itself. The phenomenon, called gravitational lensing, occurs when a massive galaxy in the foreground bends the light rays from a distant galaxy behind it, in much the same way as a magnifying glass would. When both galaxies are perfectly lined up, the light forms a circle, called an “Einstein ring”, around the foreground galaxy. If another more distant galaxy lies precisely on the same sightline, a second, larger ring will appear.
Continue reading "Stunning Einstein Ring Captured by ALMA/Hubble --"Reveals Secrets of Nature"" »
The Sun undergoes a type of seasonal variability with its activity waxing and waning over the course of nearly two years, according to a new study by a team of researchers led by the National Center for Atmospheric Research (NCAR). This behavior affects the peaks and valleys in the approximately 11-year solar cycle, sometimes amplifying and sometimes weakening the solar storms that can buffet Earth's atmosphere.
Continue reading ""Seasons of the Sun" --Solar Jet Stream Discovered" »
Astronomers have long puzzled over the appearance of supernovae that detonate out in the dark space – rather than within a host galaxy. Various theories have been proposed, the most plausible is that they might be hypervelocity stars - which are stars flung out of their host galaxy due to an unfortunate coincidence of gravitational interactions. It’s thought that such interactions may accelerate those stars up to a velocity of more than 500 to 4,000 kilometers a second – that is, more than the escape velocity of your average galaxy. These fast moving stars likely start off as one of a pair or triplet of stars that strays too close to the supermassive black hole in the center of the Galaxy.
Continue reading "Rogue Supernova in Deep Space --Are They Hypervelocity Stars that Escape Their Host Galaxy?" »
Until recently, astronomers thought the most likely way for a white dwarf to gain mass would be as a member of a close binary system with a normal sun-like star. By accumulating matter from its companion, the white dwarf can, over millions of years, nudge itself closer to the limit and explode. The companion stars are expected to survive, but astronomers find scant evidence for them, suggesting the need for an alternative model. In the merger scenario, the blast is triggered by a pair of lower-mass white dwarfs, whose orbits tighten over time until they eventually merge and explode.
Continue reading "Seeding the Cosmos! Massive Supernova Event from Merging White Dwarfs or a Single Star?" »
Did monster black holes pull the first galaxies together, or were they born inside those galaxies? According to current theories, most large galaxies harbor supermassive black holes at their core. But When these galaxies collide and their black holes merge into one massive object, they yield no information about the original black holes.
Continue reading "Monster Black Holes --"Did They Pull the 1st Galaxies Together or Born Inside?" (Weekend Feature)" »
The “information loss paradox” in black holes — a problem that has plagued physics for nearly 40 years — may not exist. That’s what some physicists have argued for years: That black holes are the ultimate vaults, entities that suck in information and then evaporate without leaving behind any clues as to what they once contained. A new University at Buffalo study finds that — contrary to what some physicists have argued for the years — information is not lost once it has entered a black hole. The research presents explicit calculations showing how information is, in fact, preserved..
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NASA's Hubble Space Telescope has photographed a set of wispy, goblin-green objects that are the ephemeral ghosts of quasars that flickered to life and then faded. The glowing structures have looping, helical, and braided shapes. "They don't fit a single pattern," said Bill Keel of the University of Alabama, Tuscaloosa, who initiated the Hubble survey. Keel believes the features offer insights into the puzzling behavior of galaxies with energetic cores. Keel said that one possible explanation is that pairs of co-orbiting black holes are powering the quasars, and this could change their brightness, like using the dimmer switch on a chandelier.
Continue reading "Colossal Ghostly Structures Found Shrouding Galaxies --Powered by Ancient Quasars" »
Two phenomena known to inhibit the potential habitability of planets — tidal forces and vigorous stellar activity — might instead help chances for life on certain planets orbiting low-mass stars, University of Washington astronomers have found.
Continue reading " "Alien Gas Giants Could Morph Into Gas-Free Habitable Worlds"" »
Many, perhaps most, stars in the Universe live their lives with companions by their sides -- in so-called binary systems. Until recently, however, the ancient RR Lyrae stars appeared, for mysterious reasons, to live their lives all alone. A recent study led by Chilean astronomers shows that RR Lyrae stars may not be as lonely as previously thought. The new research is published in Monthly Notices of the Royal Astronomical Society Letters.
Continue reading "Oldest Known Stars in the Cosmos --A "Lonely Hearts" Club?" »