Mar 26
Tags: billions of stars, cosmos, galaxy, number of stars, stars
Ever try to count all the stars in the sky? Don’t. Scientists recently announced that there may be a billion (that’s with a “b”) more stars out there than they originally thought.
A buzzy article from the Discovery News explains that astronomers “may have underestimated the tally of galaxies in some parts of the universe by as much as 90 percent.”
How could sky watchers have missed so many stars? Apparently, astronomers rely on ultraviolet light signatures to determine the number of stars in the cosmos. But that might not be the most accurate way to go about conducting a census of the universe. “In the case of very distant, old galaxies, the telltale light may not reach Earth as it is blocked by interstellar clouds of dust and gas — and, as a result, these galaxies are missed by the map-makers.” The story inspired a slew of searches on everything from “how many stars in the sky” to “how to count stars.”
More Details at Yahoo Buzz!
Dec 27
Tags: galaxy, lifeform, stars, top 10, universe, weird things
The more we look among the stars and galaxies, the weirder things seem to get.
Even space itself is puzzling, for example. Recent studies suggest that the fabric of the universe stretches more than 150 billion light-years across — in spite of the fact that the cosmos is 13.7 billion years old.
From super-fast stars to the nature of matter, here we cover other strange and mysterious elements of the universe.
10. Hypervelocity Stars
If you’ve ever gazed at the night sky, you’ve probably wished upon a shooting star (which are really meteors).
But shooting stars do exist, and they’re as rare as one in 100 million.
In 2005, astronomers discovered the first “hypervelocity” star careening out of a galaxy at nearly 530 miles per second (10 times faster than ordinary star movement).
We have ideas about what flings these rare stars into deep space, but aren’t certain; anything from off-kilter supernova explosions to supermassive black holes might be responsible.
Caption: Artist’s rendition of a hypervelocity star leaving a galaxy. Credit: Harvard-Smithsonian Center for Astrophysics
Read the Top 9 here.
Sep 15
Tags: alien planet, astronomy, planet, space science, stars
Discovering a planet around another star is no big deal these days — dozens of them have been reported in 2008 alone, and the total count now stands at more than 300.
Of course, the burgeoning exoplanet population hasn’t stopped astronomers from looking for more of them. Big gaps remain in the sampling statistics, because the most successful techniques (radial-velocity monitoring, microlensing events, and periodic transits) favor finding large bodies close to their parent stars. Far-out planets are rarely discovered this way because they have long orbital periods and even longer odds of crossing directly in front of their stars.
But it should be possible to spot alien worlds directly by imaging very young nearby stars. This game plan assumes that any outlying gas-giant planets are still glowing warmly from their recent formation, making them relatively easy pickings at infrared wavelengths. One of these came to light in 2004, though it orbits a feebly glowing brown dwarf rather than a proper star.
Full article at skyandtelescope.com
