An international team of scientists, including Carnegie's Paul Butler, has discovered that Tau Ceti, one of the closest and most Sun-like stars, may have five planets. Their work is published by Astronomy & Astrophysics and is available online.
At a distance of twelve light years and visible with a naked eye in the evening sky, Tau Ceti is the closest single star with the same spectral classification as our Sun. Its five planets are estimated to have masses between two and six times the mass of the Earth--making it the lowest-mass planetary system yet detected. One of the planets lies in the habitable zone of the star and has a mass around five times that of Earth, making it the smallest planet found to be orbiting in the habitable zone of a Sun-like star.
The international team of astronomers, led by Mikko Tuomi from the University of Hertfordshire, combined more than six-thousand observations from three different instruments and applied intensive modeling to the data. Using new techniques, the team found a method to find signals half the size previously thought possible, which greatly improves the sensitivity of searches for small planets and suggests that Tau Ceti is not a lone star but has a planetary system.
"We pioneered new data modeling techniques by adding artificial signals to the data and testing our recovery of the signals with a variety of different approaches," Tuomi said. "This significantly improved our noise modeling techniques and increased our sensitivity to find low mass planets."
Tau Ceti was chosen for this noise-modeling study because the team thought it had no signals and would be a good benchmark system to test their methods for planet detection. This is particularly true because it is so bright and similar to our own Sun. It's also one of Earth's nearest cosmic neighbors, so scientists could be able to learn about the atmospheres of these planets in the not-too-distant future.
More than 800 planets have been discovered orbiting other worlds, but planets in orbit the around the nearest Sun-like stars are particularly valuable for research.
"We are now glimpsing for the first time the secrets of our nearest companion stars and their previously hidden reservoirs of potentially habitable planets," Butler said. "This work presages the time when we will be able to directly see these planets, and search them for water, carbon dioxide, methane, and other signposts of life."
Carnegie Institution: http://www.ciw.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Defending itself like a knight in a fight, Earth can funnel material from its immediate surroundings to act as a buffer against incoming geomagnetic storms
Patsy Cline's classic country song "I Fall to Pieces," has nothing on this one.
It's only the size of a dishwasher and weighs as much as giant panda, but its inventors are hoping this spacecraft will go where no other Israeli vessel has gone before - to the moon.
About 5 million years ago, an asteroid or comet slammed into Mars so hard that rocks and other debris launched into space.
President Barack Obama's 2015 NASA budget plan includes funding for a robotic mission to an ocean-bearing moon of Jupiter and could help boost commercial ventures to fly astronauts to the International Space Station, NASA officials said on Tuesday.
It's set to come within 216,000 miles of Earth, which is closer than you think.
NASA says cooperation on International Space Station continues, but asks for funding to end reliance on Russian transport
A mysterious dark spot in downtown Tokyo. A flock of dancing dots in the Pacific. A town that's half orange, half green. Astronaut puzzlers seen from space.
Since the mid-1990s, when fuel stopped flowing from the defunct Soviet Union to North Korea, the famously hermetic country has descended into darkness.
NASA will admit on Wednesday that Luca Parmitano's space suit leaked on two space walks in July, after details on the initial incident were not properly disseminated, ABC News has learned.