The Week (US)

The farthest star ever detected

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Astronomer­s using the Hubble Space Telescope have spotted the most distant star ever seen: a blue supergiant located 9.3 billion light-years away. Dubbed Icarus, the star is at least 100 times farther away than any seen before, reports The Washington Post. Only exploding stars or entire galaxies would normally be visible at that distance. Astrophysi­cists made the discovery because of a phenomenon called “gravitatio­nal lensing,” which occurs when the gravity of a massive celestial object amplifies the light of an object behind it. In this case, a galaxy cluster moved between the Hubble and Icarus, magnifying the star’s light some 2,000 times. The effect was like “a natural telescope, much more powerful than anything we could build,” says study author Patrick Kelly, from the University of Minnesota. By now, Icarus has probably collapsed and no longer shines; astronomer­s are seeing the star as it was just 4.4 billion years after the Big Bang, which took place 13.8 billion years ago. The sighting could help scientists understand the evolution of stars in the early universe.

years, one-third of the volunteers ate their normal diet, while the rest cut their caloric intake by 15 percent. Unsurprisi­ngly, those who consumed fewer calories lost weight— about 20 pounds on average. But they also saw another benefit: Their metabolic rate, which governs the amount of energy the body requires to sustain normal daily functions, slowed by about 10 percent during sleep. “It’s important because every time we generate energy in the body, we generate byproducts,” explains lead author Leanne Redman. These so-called free radicals accumulate and cause damage to cells and organs; this damage has been linked to diabetes, cancer, Alzheimer’s, and other age-related diseases. Previous studies have shown that reducing calories can extend life in rodents and other animals, but there has been little research to see if the same is true in humans. Redman now wants to examine the effects of reducing calorie intake over a much longer period.

grounding line retreats inland, more ice is exposed to the ocean. The researcher­s found that 10.7 percent of the continent’s glaciers are melting at above-average rates, while only 1.9 percent are growing, reports TheGuardia­n.com. They concluded that each year during the six-year observatio­n period, about 80 square miles of underwater ice went afloat—an area about four times the size of Manhattan. “We can’t extrapolat­e sea level rates that come from that,” says lead author Hannes Konrad. “But to say 10 percent of Antarctica, this massive ice body, is retreating, still should be some sign of warning. It’s large.”

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