Word: dwarfs
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...type of dim red star known as an M-dwarf, only about a hundredth as bright as the sun. During the 1990s, sky surveys revealed that these puny stars are as thick as ants at a picnic, accounting for up to 70% of all the stars in the Milky Way. Because an M-dwarf is so faint, its habitable zone is much smaller, so any planet that falls within that zone would be much closer to it than Earth is to the sun. And that, says Harvard astronomer David Charbonneau, gives planet hunters a huge advantage. "Basically," he says...
Rather than looking for a stellar wobble, Charbonneau and others are watching red dwarfs for signs of their light subtly dimming as an orbiting planet passes in front of them--a sort of mini-eclipse known as a transit. "If an Earth-size planet in an Earthlike orbit passes in front of a star like the sun," he says, "it dims the star by 1 part in 10,000 or even less." Since a habitable planet around an M-dwarf is much closer--about 7 million miles (11 million km) away--the transit lasts significantly longer. And since the star...
This telltale flicker is easy to spot even from a small, ground-based telescope. So Charbonneau is setting up an array of eight 16-in. (40 cm) telescopes on Mount Hopkins, near Tucson, Ariz., and pointing them over and over at the 100 closest M-dwarfs to see if their light dims in a repeating pattern. If it does, he won't have long to wait: a habitable M-dwarf planet would have a "year" only three or four days long, so transits would happen all the time. Things will get even easier in 2009, when NASA launches a satellite...
...could provide clues to the ultimate fate of the universe. And last week, a team led by Harvard astronomers announced they had seen such shrapnel. What the team observed was a stellar explosion, called a supernova, that was caused by the merger and collision of two white dwarf stars—the shriveled-up remnants of burnt-out stars. Typically, these gigantic explosions are thought to involve only one white dwarf, and astronomers have inferred from previous studies of white dwarf supernovae that the rate of expansion of the universe is accelerating. “This one might...
...because when I went to see “The Butterfly Effect” with two friends my junior year in high school, we accidentally went an hour early. So to kill time, we went to Petsmart to look at dogs, and ended up purchasing a male Siberian dwarf hamster we named Diva.Diva led a short but action-packed life as he was passed covertly from house to house. When I found one of his other owners feeding him a pencil (“Well he sleeps in wood shavings!”) I intervened and gained full custody...