Subscribe free to our newsletters via your
. 24/7 Space News .




EXO WORLDS
First Super-Earths Discovered Around Sun-Like Stars
by Staff Writers
Washington DC (SPX) Dec 16, 2009


The bright star 61 Virginis, visible with the naked eye in the constellation Virgo, is only 28 light-years from Earth and closely resembles the Sun in size, age and other properties. Earlier studies had eliminated the possibility of a Jupiter-sized planet orbiting 61 Virginis. In this study, the researchers found evidence of three low-mass planets, the smallest of which is five times the mass of Earth and speeds around the star once every four days.

Two nearby stars have been found to harbor "super-Earths" - rocky planets larger than the Earth but smaller than ice giants such as Uranus and Neptune. Unlike previously discovered stars with super-Earths, both of the stars are similar to the Sun, suggesting to scientists that low-mass planets may be common around nearby stars.

"Over the last 12 years or so nearly 400 planets have been found, and the vast majority of them have been very large - Jupiter mass or even larger," says researcher Paul Butler of the Carnegie Institution's Department of Terrestrial Magnetism. "These latest planets are part of a new trend of finding much smaller planets - planets that are more comparable to Earth."

The international team of researchers, co-led by Butler and Steven Vogt of the University of California, Santa Cruz, was able to detect the new planetary systems by combining data from observations spanning several years at the W. M. Keck Observatory in Hawaii and the Anglo-Australian Telescope in New South Wales, Australia.

The researchers used the subtle "wobbling" of the stars caused by the planets' gravitational pull to determine the planets' size and orbits. Greg Henry at Tennessee State University independently monitored the brightness of the stars to rule out stellar "jitter" - roiling of gases on a star's surface that can be confused with a planet-induced wobble.

The bright star 61 Virginis, visible with the naked eye in the constellation Virgo, is only 28 light-years from Earth and closely resembles the Sun in size, age and other properties.

Earlier studies had eliminated the possibility of a Jupiter-sized planet orbiting 61 Virginis. In this study, the researchers found evidence of three low-mass planets, the smallest of which is five times the mass of Earth and speeds around the star once every four days.

Butler points out that the signal produced by this planet was one of the smallest ever detected. "One has to be very cautious when you claim a discovery," he says. "What gives us confidence is that we see the signal from two separate telescopes, and the two signals match up perfectly."

The other newly-discovered system orbits the star HD 1461, located 76 light-years from Earth. HD 1461 also closely resembles the Sun and is visible in the constellation Cetus. The researchers found clear evidence for one planet 7.5 times the mass of Earth and possible indications of two others.

The 7.5-Earth-mass planet, designated HD 1461b, is intermediate in size between Earth and Uranus. It orbits its star once every six days.

These planets have orbits close to their stars and so they would be too hot to support life or liquid water. But Butler says that they point the way toward finding similar planets in similar orbits around nearby M-dwarfs, stars that are typically less than half the mass of the Sun and typically put out less than two percent the Sun's energy.

"These sorts of planets around M dwarfs actually would be in a liquid water zone," he says. "So we are knocking on the door right now of being able to find habitable planets."

The discoveries are reported in two papers accepted for publication in the Astrophysical Journal. In addition to Vogt and Butler, the coauthors of the two papers include Eugenio Rivera, Greg Laughlin, and Stefano Meschiari of the University of California, Santa Cruz; Greg Henry at Tennessee State University; Chris Tinney, Rob Wittenmyer, and Jeremy Bailey of the University of New South Wales, Australia; Simon O'Toole of the Anglo-Australian Observatory, Australia; Hugh Jones of the University of Hertfordshire, U.K.; Brad Carter of the University of Southern Queensland, Australia; and Konstantin Batygin of the California Institute of Technology.

.


Related Links
Carnegie Institution
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





EXO WORLDS
Low Mass Planets May Be Common Around Nearby Stars
Santa Cruz CA (SPX) Dec 15, 2009
An international team of planet hunters has discovered as many as six low-mass planets around two nearby Sun-like stars, including two "super-Earths" with masses 5 and 7.5 times the mass of Earth. The researchers, led by Steven Vogt of the University of California, Santa Cruz, and Paul Butler of the Carnegie Institution of Washington, said the two "super-Earths" are the first ones found around ... read more


EXO WORLDS
Biosatellite To The Moon

Is There Life On The Moon

Views Of The World Under The Moon

Researcher Delighted That LCROSS Confirms Lunar Prospector Findings

EXO WORLDS
Methane study favors life on Mars theory

Trough Deposits On Mars Point To Complex Hydrologic Past

Martian Moon Duo

The Meandering Channels Of Mars

EXO WORLDS
NASA, Saudi Arabia partner on research

Cuts To Human Spaceflight Program Harms Aerospace Workforce, US Economy, And National Security

NASA announces moon design competition

Japan's 'space beer' sparkles among drinkers

EXO WORLDS
China Launches First Public-Welfare Mini Satellite

Chang'e-1 Has Blazed A New Trail In China's Deep Space Exploration

China To Launch Second Lunar Probe In 2010

China To Launch Research Satellite In Near Future

EXO WORLDS
Russia To Launch MIM1 Module To ISS Next Year

Russia Plans To Send 10 Spacecraft To ISS Next Year

SpaceX Begins NASA Astronaut Training For Dragon Spacecraft COTS Program

Four "Butterflynauts" Emerge On ISS

EXO WORLDS
NASA's WISE Eye On The Universe Begins All-Sky Survey Mission

WISE Launch Rescheduled For December 14

Helios 2B Military Observation Platform Given "Go" For Launch

Arianespace Marks 30 Years Of Launch Services Excellence

EXO WORLDS
First Super-Earths Discovered Around Sun-Like Stars

Low Mass Planets May Be Common Around Nearby Stars

Superior Super Earths

UCF Space Experiment To Fly On New Rocket Ship

EXO WORLDS
China starts building bridge linking Hong Kong, Macau

Space Debris Remediation Seen As A New Business Area

Cryostat To Fly On WISE Mission

China's monopoly on 'green' minerals




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement