17 Apr 2019, 17:51 UTC Next Previous
2 Apr 2019, 17:19 UTC Astronomers used the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) to make the first direct image of a dusty, doughnut-shaped feature surrounding the supermassive black hole at the core of one of the most powerful radio galaxies in the Universe — a feature first postulated by theorists nearly four decades ago as an essential part of such objects.The scientists studied Cygnus A, a galaxy some 760 million light-years from Earth. The galaxy harbors a black hole at its core that is 2.5 billion times more massive then the Sun. As the black hole’s powerful gravitational pull draws in surrounding material, it also propels superfast jets of material traveling outward at nearly the speed of light, producing spectacular “lobes” of bright radio emission.Black hole-powered “central engines” producing bright emission at various wavelengths, and jets extending far beyond the galaxy are common to many galaxies, but show different properties when observed. Those differences led to a variety of names, such as quasars, blazars, or Seyfert galaxies. To explain the differences, theorists constructed a “unified model” with a common set of features that would show different properties depending on the angle from which they are viewed.The unified model includes the ... Next Previous
29 Mar 2019, 16:12 UTC Next Previous
27 Mar 2019, 11:00 UTC The GRAVITY instrument on ESO’s Very Large Telescope Interferometer (VLTI) has made the first direct observation of an exoplanet using optical interferometry. This method revealed a complex exoplanetary atmosphere with clouds of iron and silicates swirling in a planet-wide storm. The technique presents unique possibilities for characterising many of the exoplanets known today. Next Previous
26 Mar 2019, 17:26 UTC ITHACA, N.Y. – NASA’s new Transiting Exoplanet Survey Satellite (TESS) is designed to ferret out habitable exoplanets, but with hundreds of thousands of sunlike and smaller stars in its camera views, which of those stars could host planets like our own? A team of astronomers from Cornell, Lehigh University and Vanderbilt University has identified the most promising targets for this search in the new “TESS Habitable Zone Star Catalog,” published March 26 in Astrophysical Journal Letters. Lead author Lisa Kaltenegger, professor of astronomy in the College of Arts and Sciences and director of Cornell’s Carl Sagan Institute, is a member of the TESS science team. The catalog identifies 1,822 stars for which TESS is sensitive enough to spot Earth-like planets just a bit larger than Earth that receive radiation from their star equivalent to what Earth receives from our sun. For 408 stars, TESS can glimpse a planet just as small as Earth, with similar irradiation, in one transit alone. “Life could exist on all sorts of worlds, but the kind we know can support life is our own, so it makes sense to first look for Earth-like planets,” Kaltenegger said. “This catalog tells us around which stars we can ... Next Previous
19 Mar 2019, 19:55 UTC Researchers have detected a radio signal from abundant interstellar dust in MACS0416_Y1, a galaxy 13.2 billion light-years away in the constellation Eridanus. Standard models can’t explain this much dust in a galaxy this young, forcing us to rethink the history of star formation. Researchers now think MACS0416_Y1 experienced staggered star formation with two intense starburst periods 300 million and 600 million years after the Big Bang with a quiet phase in between.Stars are the main players in the Universe, but they are supported by the unseen backstage stagehands: stardust and gas. Cosmic clouds of dust and gas are the sites of star formation and masterful storytellers of the cosmic history.“Dust and relatively heavy elements such as oxygen are disseminated by the deaths of stars,” said Yoichi Tamura, an associate professor at Nagoya University and the lead author of the research paper, “Therefore, a detection of dust at some point in time indicates that a number of stars have already formed and died well before that point.”Using ALMA (Atacama Large Millimeter/submillimeter Array), Tamura and his team observed the distant galaxy MACS0416_Y1. Because of the finite speed of light, the radio waves we observe from this galaxy today had to travel for ... Next Previous
19 Mar 2019, 16:00 UTC Astronomers using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) have found a pulsar speeding away from its presumed birthplace at nearly 700 miles per second, with its trail pointing directly back at the center of a shell of debris from the supernova explosion that created it. The discovery is providing important insights into how pulsars — superdense neutron stars left over after a massive star explodes — can get a “kick” of speed from the explosion.“This pulsar has completely escaped the remnant of debris from the supernova explosion,” said Frank Schinzel, of the National Radio Astronomy Observatory (NRAO). “It’s very rare for a pulsar to get enough of a kick for us to see this,” he added.The pulsar, dubbed PSR J0002+6216, about 6,500 light-years from Earth, was discovered in 2017 by a citizen-science project called Einstein@Home. That project uses computer time donated by volunteers to analyze data from NASA’s Fermi Gamma-ray Space Telescope. So far, using more than 10,000 years of computing time, the project has discovered a total of 23 pulsars.Radio observations with the VLA clearly show the pulsar outside the supernova remnant, with a tail of shocked particles and magnetic energy some 13 light-years ... Next Previous
NASA Breaking News 23 Apr 2019, 18:37 UTC NASA’s Mars InSight lander has measured and recorded for the first time ever a likely “marsquake.”
Canada-France-Hawaii Telescope 23 Apr 2019, 08:31 UTC A team of researchers from the Strasbourg Astronomical Observatory, Bologna Observatory and the University of Stockholm has identified a stream of stars that was torn off the globular cluster Omega Centauri. Searching through the 1.7 billion stars observed by the ESA Gaia mission, they have identified 309 stars that suggest that this globular cluster may actually be the remnant of a dwarf galaxy that is being torn apart by the gravitational forces of our Galaxy.
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NASA Scientist to Discuss “Apollo at 50: The Lasting Effect of Exploration of the Lunar Surface” at Library of Congress Lecture22 Apr 2019, 13:50 UTC The public is invited to a free talk called ‘Apollo at 50: The Lasting Effect of Exploration of the Lunar Surface on Our Current Exploration of the Moon,' with Dr. Noah Petro, Project Scientist for the Lunar Reconnaissance Orbiter or LRO mission. The talk will occur in the Pickford theater, third floor, Madison Building, 101 Independence Avenue SE, Library of Congress, Washington, D.C., on Tuesday, April 30 from 11:30 a.m. to 12:30 p.m. EDT.
NASA's Goddard Space Flight Center 17 Apr 2019, 15:00 UTC How do you explore the interior of a planet without ever touching down on it? Start by watching the way the planet spins, then measure how your spacecraft orbits it — very, very carefully. This is exactly what NASA planetary scientists did, using data from the agency’s former mission to Mercury.
NASA's Goddard Space Flight Center 17 Apr 2019, 12:49 UTC The newly forming stars in the tail are mysterious because processes common in large groups of galaxies should make it difficult for new stars to emerge. Most galaxies live in groups — for example, the Milky Way is a member of the Local Group, which also contains galaxies like Andromeda and the Triangulum spiral. Some galaxies reside in much larger gatherings of hundreds or even thousands of galaxies known as a galaxy cluster. The “jellyfish” galaxy ESO 137-001 is part of a cluster called Abell 3627.
NASA's Chandra X-ray Observatory 16 Apr 2019, 18:22 UTC A neutron star merger without an observed gamma-ray burst has been discovered using NASA's Chandra X-ray Observatory.
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Centauri Dreams 24 Apr 2019, 16:59 UTC The transit method has proven invaluable for exoplanet detection, as the runaway success of the Kepler/K2 mission demonstrates. But stars where planets have been detected with this method are still capable of revealing further secrets. Consider Kepler-47. Here we have a circumbinary system some 3340 light years away in the direction of the constellation Cygnus, and as we are now learning about circumbinaries — planets that orbit two stars — the alignment of the orbital plane of the planet is likely to change with time.
astrobites 24 Apr 2019, 16:15 UTC For years now it has been widely held that Mars had an abundance of liquid water in its early history that some scientists believe was removed through an extreme global warming scenario. In 2017 the Mars Reconnaissance Orbiter found evidence of water ice deposits under the poles of Mars. Then in 2018 the Mars Express spacecraft found, using radar, evidence of liquid deep under the ice. Liquid water requires high pressures and temperatures, not believed to be possible on Mars currently, which led the authors of this paper to hypothesize that heating deep under the Martian south pole is responsible for melting the ice.
Chandra X-ray Observatory Blog 24 Apr 2019, 14:46 UTC A neutron star is the compact object formed after a supernova explosion occurring in the late evolutionary stage of a massive star, and it is one of the most mysterious objects in the universe. It is composed of almost all neutrons, and has some extreme physical properties such as ultra-high density and a super-strong magnetic field. It is an excellent natural laboratory for testing basic physical laws. However, up to now, our understanding about the basic properties of neutron stars (e.g., the equation of state, which describes the relation among pressure, density, etc.) is still relatively vague.
Scientific American 24 Apr 2019, 11:00 UTC One of astronomy’s great explainers tells you about the Event Horizon Telescope’s image and plenty more
New Scientist 23 Apr 2019, 19:53 UTC Mars is shaking. NASA’s InSight lander has detected its first marsquake, a rumbling from the planet’s interior, and it may have felt three more. These quakes could help us learn how much water is hiding deep within the planet.
Centauri Dreams 23 Apr 2019, 17:14 UTC About 250 light years away there is a faint object that is on the borderline between brown dwarf and star. Only a tenth of the radius of our Sun, ULAS J224940.13-011236.9 was actually too faint for most telescopes to observe until a huge flare lit it up, turning this L dwarf, among the lowest mass objects that can still be considered a star, 10,000 times brighter than it was before. Very cool compared to the average red dwarf, L dwarfs emit radiation primarily in the infrared.