An international team of astrophysicists has for the first time witnessed a black hole swallowing a star and ejecting a flare of matter moving at nearly the speed of light. The scientists tracked the Sun-sized star in the galaxy PGC 43234 some 300 million light-years away as it shifted from its customary path, slipped into the gravitational pull of the supermassive black hole and was sucked in.
A team of astronomers using ESO’s Very Large Telescope has captured the most detailed images ever of the hypergiant star VY Canis Majoris. These observations show how the unexpectedly large size of the particles of dust surrounding the star enable it to lose an enormous amount of mass as it begins to die. This process, understood now for the first time, is necessary to prepare such gigantic stars to meet explosive demises as supernovae.
A star called KIC 8462852 has been in the news recently for unexplained and bizarre behaviour. NASA’s Kepler mission had monitored the star for four years, observing two unusual incidents, in 2011 and 2013, when the star’s light dimmed in dramatic, never-before-seen ways. Something had passed in front of the star and blocked its light, but what?
Computer simulations of the evolution of matter distribution in the universe predict hundreds of low mass dwarf galaxies for every Milky Way-like galaxy. An international team of astronomers recently announced the discovery of an astonishing number of faint low surface brightness dwarf galaxies in the Fornax Cluster, suggesting that the “missing satellites” are now being found.
Dark matter is an invisible, mysterious substance that makes up about 27 percent of all matter and energy in the universe. A new NASA study publishing this week proposes that when a stream of dark matter particles goes through a planet, the planet’s gravity bends and focuses the particles into an ultra-dense filament, or “hair,” of dark matter. In theory, there should be many such hairs sprouting from Earth.
Despite their name, planetary nebulae have nothing to do with planets. They were described as such by early astronomers whose telescopes showed them as glowing disc-like objects, but we now know that they represent the final stage of activity of stars like our Sun. A way of estimating more accurate distances to planetary nebulae dispersed across our Galaxy has just been announced.
A study just published by University of Texas at Austin assistant professor Steven Finkelstein and colleagues reveals that galaxies were more efficient at making stars when the universe was younger. The announcement explains the team’s discovery that there are a lot more bright, highly star-forming galaxies in the early universe than scientists previously thought.
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