News (Page 463)

Neutron star with measured at 11 kilometers radius An international research team led by members of the Max Planck Institute for Gravitational Physics (Albert Einstein Institute; AEI) has obtained new measurements of how big neutron stars are. To do so, they combined a general first-principles description of the unknown behavior of neutron star matter with multi-messenger observations of the binary neutron star merger GW170817. Their results, which appeared in Nature Astronomy today, are more stringent by a factor of two than previous limits and show that a typical neutron star has a radius close to 11 kilometers. They also find that neutron stars merging withRead More →

Radio galaxy NGC 3894 investigated with Fermi Using the Large Area Telescope (LAT) onboard NASA’s Fermi spacecraft, astronomers have investigated a nearby radio galaxy known as NGC 3894. Results of the study, presented in a paper published March 3, confirm the galaxy’s young age and provide more insights into its properties. phys.org Go to SourceRead More →

Solved: The mystery of the expansion of the universe The Earth, solar system, the entire Milky Way and the few thousand galaxies closest to us move in a vast “bubble” that is 250 million light years in diameter, where the average density of matter is half as high as for the rest of the universe. This is the hypothesis advanced by a theoretical physicist from the University of Geneva (UNIGE) to solve a conundrum that has been splitting the scientific community for a decade: At what speed is the universe expanding? Until now, at least two independent calculation methods have arrived at two values thatRead More →

New technique could elucidate earliest stages of planet’s life A new kind of astronomical observation helped reveal the possible evolutionary history of a baby Neptune-like exoplanet. phys.org Go to SourceRead More →

Discovery points to origin of mysterious ultraviolet radiation Billions of lightyears away, gigantic clouds of hydrogen gas produce a special kind of radiation, a type of ultraviolet light known as Lyman-alpha emissions. The enormous clouds emitting the light are Lyman-alpha blobs (LABs). LABs are several times larger than our Milky Way galaxy, yet were only discovered 20 years ago. An extremely powerful energy source is necessary to produce this radiation—think the energy output equivalent of billions of our sun—but scientists debate what that energy source could be. phys.org Go to SourceRead More →

Turbulent convection at the heart of stellar activity In their interiors, stars are structured in a layered, onion-like fashion. In those with solar-like temperatures, the core is followed by the radiation zone. There, the heat from within is led outwards by means of radiation. As the stellar plasma becomes cooler farther outside, heat transport is dominated by plasma flows: hot plasma from within rises to the surface, cools, and sinks down again. This process is called convection. At the same time, the star’s rotation, which depends on stellar latitude, introduces shear movements. Together, both processes twist and twirl magnetic field lines and create a star’sRead More →

Astronomers pinpoint rare binary brown dwarf Astronomers working on ‘first light’ results from a newly commissioned telescope in Chile made a chance discovery that led to the identification of a rare eclipsing binary brown dwarf system. phys.org Go to SourceRead More →

New type of pulsating star discovered A star that pulsates on just one side has been discovered in the Milky Way about 1500 light years from Earth. It is the first of its kind to be found and scientists expect to find many more similar systems as technology to listen inside the beating hearts of stars improves. phys.org Go to SourceRead More →

Astronomers identify nearly 3,000 candidate stars of a nearby star-forming galaxy Using the United Kingdom Infrared Telescope (UKIRT) and NASA’s Spitzer Space Telescope, astronomers have conducted photometric observations of a nearby star-forming galaxy known as NGC 6822. They have identified nearly 3,000 candidate stars of this galaxy, which is reported in a paper published February 27 on the arXiv pre-print server. phys.org Go to SourceRead More →

Image: Hubble spies galactic traffic jam The barred spiral galaxy NGC 3887, seen here as viewed by the Wide Field Camera 3 aboard the NASA/ESA Hubble Space Telescope, lies over 60 million light-years away from us in the southern constellation of Crater (the Cup). It was discovered on Dec. 31, 1785, by astronomer William Herschel. phys.org Go to SourceRead More →

Safety zone saves giant moons from fatal plunge Numerical simulations show that the temperature gradient in the gas disk around a young gas giant planet could play a critical role in the development of a satellite system dominated by a single large moon, similar to Titan in the Saturn system. Researchers found that dust in the circumplanetary disk can create a “safety zone” that keeps the moon from falling into the planet as the system evolves. phys.org Go to SourceRead More →

Astronomers report most distant blazar ever observed Although it may have a difficult designation to remember, PSO J030947.49+271757.31, the most distant blazar observed to date, reveals important details about ancient black holes and places tight constraints on theories of the evolution of the universe. Its light originated when the universe was less than 1 billion years old, almost 13 billion years ago. phys.org Go to SourceRead More →