Free Republic

Sorry, E.T. lovers, but the results of a new study make it far less likely that KIC 8462852, popularly known as Tabby's star, is the home of industrious aliens who are gradually enclosing it in a vast shell called a Dyson sphere. Public interest in the star, which sits about 1,480 light-years away in the constellation Cygnus, began last fall when Yale astronomer Tabetha ("Tabby") Boyajian and colleagues posted a paper on an astronomy preprint server reporting that "planet hunters" - a citizen science group formed to search data from the Kepler space telescope for evidence of exoplanets - had...

Theories surrounding the star system KIC 8462852, also known as Tabby's Star, ranged from comets to an "alien megastructure" after the online astronomy crowdsourcing site Planet Hunter discovered an unusual light fluctuation in the star system a few years ago. A new analysis of KIC 8462852 shows that the star system, which lies about 1,500 light years away, has been gradually dimming for more than a century, and it's likely not caused by a cloud of orbiting comets. Bradley Schaefer, a physics and astronomy professor at Louisiana State University, examined data from a Harvard University archive of digitally scanned photographic...

upermassive black holes are the most extreme objects in the known universe, with masses millions or even billions of times the mass of our sun. Now astronomers have been able to study one of these behemoths inside a strange, distant quasar and they’ve made an astonishing discovery — it’s spinning one-third the speed of light. Studying a supermassive black hole some 3.5 billion light-years away is no easy feat, but this isn’t a regular object: it’s a quasar that shows quasi-periodic brightening events every 12 years or so — a fact that has helped astronomers reveal its extreme nature. Quasars...

Explanation: Giant elliptical galaxy M60 and spiral galaxy NGC 4647 do look like an odd couple in this sharp cosmic portrait from the Hubble Space Telescope. But they are found in a region of space where galaxies tend to gather, on the eastern side of the nearby Virgo Galaxy Cluster. About 54 million light-years distant, bright M60's simpler egg-like shape is created by its randomly swarming older stars, while NGC 4647's young blue stars, gas and dust are organized into winding arms rotating in a flattened disk. Spiral NGC 4647 is estimated to be more distant than M60, some 63...

Explanation: A mere 2.5 million light-years away, the Andromeda Galaxy, also known as M31, really is just next door as large galaxies go. In this (inset) scan, image data from NASA's Nuclear Spectrosopic Telescope Array has yielded the best high-energy X-ray view yet of our large neighboring spiral, revealing some 40 extreme sources of X-rays, X-ray binary star systems that contain a black hole or neutron star orbiting a more normal stellar companion. In fact, larger Andromeda and our own Milky Way are the most massive members of the local galaxy group. Andromeda is close enough that NuSTAR can examine...

Explanation: This dance is to the death. Along the way, as these two large galaxies duel, a cosmic bridge of stars, gas, and dust currently stretches over 75,000 light-years and joins them. The bridge itself is strong evidence that these two immense star systems have passed close to each other and experienced violent tides induced by mutual gravity. As further evidence, the face-on spiral galaxy on the right, also known as NGC 3808A, exhibits many young blue star clusters produced in a burst of star formation. The twisted edge-on spiral on the left (NGC 3808B) seems to be wrapped in...

Explanation: What's the closest active galaxy to planet Earth? That would be Centaurus A, only 11 million light-years distant. Spanning over 60,000 light-years, the peculiar elliptical galaxy is also known as NGC 5128. Forged in a collision of two otherwise normal galaxies, Centaurus A's fantastic jumble of young blue star clusters, pinkish star forming regions, and imposing dark dust lanes are seen here in remarkable detail. The colorful galaxy portrait is a composite of image data from space- and ground-based telescopes large and small. Near the galaxy's center, left over cosmic debris is steadily being consumed by a central black...

ESO's VISTA survey telescope has spied a horde of previously hidden massive galaxies that existed when the Universe was in its infancy. By discovering and studying more of these galaxies than ever before, astronomers have for the first time found out exactly when such monster galaxies first appeared. The newly discovered massive galaxies are marked on this image of the UltraVISTA field. [RED CIRCLES] ================================================================================================================ Astronomers have detected something baffling at the furthest frontiers of our observable universe: massive galaxies -- lots of massive galaxies -- that shouldn't even exist. Depending on the wavelength you observe the universe in,...

"We either caught something shortly after an event like two planets crashing together or alien intelligence," said Dr. Gerald Harp, senior scientist at the SETI Institute in Mountain View, California, referring to the baffling light variations seen in the Kepler star KIC 8462852. And he and a team from the Institute are working hard at this moment to determine which of the two it is. Beginning last Friday (Oct. 16), the Institute's Allen Telescope Array (ATA) was taken off its normal survey schedule and instead focused on KIC 8462852, one of the 150,000-plus stars studied by NASA's Kepler Mission to...

The paper doesn’t mention aliens, and it doesn’t even imply aliens. Not directly, at least. But the astronomers found a star so odd, with behavior so difficult to explain, that it’s clear something weird is happening there. And some of the astronomers who did the work are now looking into the idea that what they’ve found might (might!) be due to aliens. But don’t let this idea run away with you. The scientists involved are being very skeptical and approaching this the right way. The star is called KIC 8462852, and it’s one of more than a hundred thousand stars...

The mystery behind a strangely dimming star could soon be solved. Astronomers around the world are keeping a close eye on the star KIC 8462852, which has dimmed dramatically numerous times over the past few years, dropping in brightness by up to 22 percent. These big dips have spurred speculation that the star may be surrounded by some type of alien megastructure — a hypothesis that will be put to the test if and when KIC 8462852 dims again. "As long as one of those events occurs again, we should be able to catch it in the act, and then...

“It was kind of unbelievable that it was real data,” said Yale University astronomer Tabetha Boyajian. “We were scratching our heads. For any idea that came up there was always something that would argue against it.” She was talking to the New Scientist about KIC 8462852, a distant star with a very unusual flickering habit. Something was making the star dim drastically every few years, and she wasn’t sure what. Boyajian wrote up a paper on possible explanations for the star’s bizarre behavior, and it was published recently in the Monthly Notices of the Royal Astronomical Society. But she also...

Explanation: Pointy stars and peculiar galaxies span this cosmic snapshot, a telescopic view toward the well-groomed constellation Coma Berenices. Bright enough to show off diffraction spikes, the stars are in the foreground of the scene, well within our own Milky Way. But the two prominent galaxies lie far beyond our own, some 41 million light-years distant. Also known as NGC 4747, the smaller distorted galaxy at left is the 159th entry in the Arp Atlas of Peculiar Galaxies, with extensive tidal tails indicative of strong gravitational interactions in its past. At about a 100,000 light-years across, its likely companion on...

In the center of most galaxies (ours included) there is a supermassive black hole that holds everything together. However, one galaxy 10.5 billion light years away looks like it might have two black holes, and just like in Highlander, there can be only one. Scientists believe the pair are going to crash into each other in just 21 years. This could provide an unprecedented opportunity to observe the mind-boggling physics of such an event. The galaxy in question doesn’t have a snazzy name — it’s known only as PSO J334.2028+01.4075. It’s what is known as a quasar, or an “active...

Explanation: Long ago, far away, a star exploded. Supernova 1994D, visible as the bright spot on the lower left, occurred in the outskirts of disk galaxy NGC 4526. Supernova 1994D was not of interest for how different it was, but rather for how similar it was to other supernovae. In fact, the light emitted during the weeks after its explosion caused it to be given the familiar designation of a Type Ia supernova. If all Type 1a supernovae have the same intrinsic brightness, then the dimmer a supernova appears, the farther away it must be. By calibrating a precise brightness-distance...

Scientists using NASA’s Hubble Space Telescope have discovered that the immense halo of gas enveloping the Andromeda galaxy, our nearest massive galactic neighbor, is about six times larger and 1,000 times more massive than previously measured. The dark, nearly invisible halo stretches about a million light-years from its host galaxy, halfway to our own Milky Way galaxy. This finding promises to tell astronomers more about the evolution and structure of majestic giant spirals, one of the most common types of galaxies in the universe. “Halos are the gaseous atmospheres of galaxies. The properties of these gaseous halos control the rate...

Certain types of supernovae, or exploding stars, are more diverse than previously thought, a University of Arizona-led team of astronomers has discovered. The results, reported in two papers published in the Astrophysical Journal, have implications for big cosmological questions, such as how fast the universe has been expanding since the Big Bang. Most importantly, the findings hint at the possibility that the acceleration of the expansion of the universe might not be quite as fast as textbooks say. The team, led by UA astronomer Peter A. Milne, discovered that type Ia supernovae, which have been considered so uniform that cosmologists...

Explanation: Mysterious Hanny's Voorwerp, Dutch for "Hanny's Object", is really enormous, about the size of the Milky Way Galaxy and glowing strongly in the greenish light produced by ionized oxygen atoms. It is thought to be a tidal tail of material left by an ancient galaxy merger, illuminated and ionized by the outburst of a quasar inhabiting the center of distant spiral galaxy IC 2497. Its exciting 2007 discovery by Dutch schoolteacher Hanny van Arkel while participating online in the Galaxy Zoo project has since inspired a search and discovery of eight more eerie green cosmic features. Imaged in these...

Explanation: What dark structures arise from the Pelican Nebula? Visible as a bird-shaped nebula toward the constellation of a bird (Cygnus, the Swan), the Pelican Nebula is a place dotted with newly formed stars but fouled with dark dust. These smoke-sized dust grains formed in the cool atmospheres of young stars and were dispersed by stellar winds and explosions. Impressive Herbig-Haro jets are seen emitted by a star on the right that is helping to destroy the light year-long dust pillar that contains it. The featured image was scientifically-colored to emphasize light emitted by small amounts of ionized nitrogen, oxygen,...

Scientists name new ‘object’ SDSS J0100+2802 and say it is 12.8bn light years from Earth and was formed just 900m years after the Big Bang *************************************************************A monster black hole powering “the brightest lighthouse in the distant universe” has been discovered that is 12bn times more massive than the sun, scientists have revealed.The extraordinary object is at the centre of a quasar - an intensely powerful galactic radiation source - with a million billion times the sun’s energy output.For years the nature of quasars, discovered in 1963, remained a mystery. Today scientists believe they are generated by matter heating up as...