News (Page 750)

Chandra finds stellar duos banished from galaxies Scientists have found evidence that pairs of stars have been kicked out of their host galaxies. This discovery, made using data from NASA’s Chandra X-ray Observatory, is one of the clearest examples of stellar pairs being expelled from their galactic base. phys.org Go to SourceRead More →

Pushing stargazing to the limits with the world’s largest gamma-ray observatory To discover the secrets of exploding stars or black holes, scientists have been focusing on the gamma rays they emit. However, gamma rays don’t pass through the Earth’s atmosphere, making them difficult to study. To find what high-energy process a gamma ray originates from, scientists have been observing the cascades of secondary particles produced when these rays hit the atmosphere. The cascades—which create blue flashes of light called Cherenkov light after the Russian physicist who discovered them—only last a few billionths of a second and are invisible to the naked eye. What’s more, they’reRead More →

Stolen comets and free-floating objects Our solar system may contain alien comets that were stolen from another star flying past 4.5 billion years ago. Far away in a distant cluster of young stars, a similar close encounter might have also sent the inter-stellar visitor “Oumuamua” flying on its way toward us, and there must be many more of these free-floating objects in the galaxy. These are results of a new study by astrophysicists at the University of Zurich. phys.org Go to SourceRead More →

Evidence of new magnetic transitions in late-type dwarfs from Gaia DR2 Since the second Gaia data release on the 25th April 2018, astrophysicists have had at their disposal an unprecedented wealth of information not only on distances and motions of stars in the galaxy, but also on many other stellar parameters that came along by exploiting the instrumentation aboard the satellite and the unique characteristics of the mission. Multiple observations of the same star, required to derive its distance and motion, also produced parameters related to stellar variability. Data for stars with spots on the surface similar to those on our Sun, in particular, provideRead More →

Giant planets and comets battling in the circumstellar disk around HD 163296 In a study appearing today in the Astrophysical Journal, an INAF-lead team of researchers explored whether the anomalous features in the dust and gas distributions of HD 163296’s disk revealed by ALMA’s observations could arise from the interaction of the giant planets with planetesimals, a component of the disk previously unaccounted for. phys.org Go to SourceRead More →

Astronomers investigate pulsar wind nebula DA 495 Astronomers have carried out a multiwavelength investigation of a pulsar wind nebula (PWN), designated DA 495, to unveil its mysterious physical nature. Results of the study, based on observations using HAWC and VERITAS ground-based observatories as well as NASA’s NuSTAR spacecraft, are presented in a paper published May 17 on arXiv.org. phys.org Go to SourceRead More →

World celebrates centenary of confirmation of relativity Celebrations are underway across the globe to commemorate 100 years since a UK-led expedition confirmed Einstein’s general theory of relativity. The theory fundamentally changed our understanding of physics and astronomy, and underpins critical modern technologies such as the satellite-based Global Positioning System (GPS). A series of public events in the UK and around the world will mark this seminal anniversary. phys.org Go to SourceRead More →

Meteor magnets in outer space—study finds elusive giant planets Astronomers believe planets like Jupiter shield us from space objects that would otherwise slam into Earth. Now they’re closer to learning whether giant planets act as guardians of solar systems elsewhere in the galaxy. phys.org Go to SourceRead More →

Hubble spies curious galaxy moving a little closer This Hubble image stars Messier 90, a beautiful spiral galaxy located roughly 60 million light-years from the Milky Way in the constellation of Virgo (the Virgin). The galaxy is part of the Virgo Cluster, a gathering of galaxies that is over 1,200 strong. phys.org Go to SourceRead More →

Video: 100 years of gravity One hundred years ago this month, observations performed during a total solar eclipse proved for the first time the gravitational bending of light predicted by Albert Einstein’s new theory of gravity, general relativity. In this video, Günther Hasinger, ESA Director of Science, reflects on this historic measurement that inaugurated a century of exciting experiments, investigating gravity on Earth and in space and proving general relativity in ever greater detail. phys.org Go to SourceRead More →

Scientists uncover exotic matter in the sun’s atmosphere Scientists from Ireland and France today announced a major new finding about how matter behaves in the extreme conditions of the Sun’s atmosphere. phys.org Go to SourceRead More →

New catalogue of 12,000 X-ray spectral lines X-ray sources in the sky radiate “bar codes” revealing their properties. These bar codes consist of narrow peaks and troughs within the source’s spectrum. The RGS instrument on the satellite XMM-Newton was built to find these bars—or spectral lines. Astronomer Junjie Mao and his colleagues at SRON and ESA have now created a catalogue filled with 12,000 X-ray lines, which astronomers can use to conduct large-scale surveys among the stellar population. They have reported its development in Astronomy & Astrophysics. phys.org Go to SourceRead More →