Dying stars may host habitable planets with life
- Elections 2014 LIVE: Kejriwal holds roadshow in Varanasi before filing nomination
- Mulayam Yadav calls Narendra Modi a liar, says he changes 500 kurtas a day
- Bhavnagar model: Muslim buys house, canât move in
- 12-yr-olds also voted in this Bihar village
- Shazia says Muslims should become 'communal' when they vote
Dying stars may host Earth-like planets with life, and scientists might be able to detect them within the next decade, astronomers say.
Researchers have found that we could detect oxygen in the atmosphere of a white dwarf's planet much more easily than for an Earth-like planet orbiting a Sun-like star.
"In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs," said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA).
Recent research by CfA astronomers Courtney Dressing and David Charbonneau showed that the closest habitable planet is likely toorbit a red dwarf star - a cool, low-mass star undergoing nuclear fusion.
Since a red dwarf, although smaller and fainter than the sun, is much larger and brighter than a white dwarf, its glare would overwhelm the faint signal from an orbiting planet's atmosphere.
When a star like the Sun dies, it puffs off its outer layers, leaving behind a hot core called a white dwarf. A typical white dwarf is about the size of Earth. It slowly cools and fades over time, but it can retain heat long enough to warm a nearby world for billions of years.
Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. A habitable planet would circle the white dwarf once every 10 hours at a distance of about a million miles.
Before a star becomes a white dwarf it swells into a red giant, engulfing and destroying any nearby planets. Therefore,a planet would have to arrive in the habitable zone after the star evolved into a white dwarf.
Researchers said a planet could form from leftover dust and gas - making it a second-generation world or migrate inward from a larger distance.
- Run Away Style
- Stakes high for AIADMK, DMK as TN goes to polls
- Six Bengal constituencies go to poll tomorrow in second phase
- Whistleblower alleged kickbacks, favours in ‘thin client’ procurement; NDA never completed inquiry
- Pune AAP volunteers all set to hit campaign trail in Varanasi
- ‘Interstate’ gang of chain snatchers held; gold worth Rs 80 lakh seized