Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First super-Earths discovered around Sun-like stars

15.12.2009
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.

The research was supported by the National Science Foundation, and NASA's Office of Space Science, the NASA Keck PI program, the Carnegie Institution for Science, and the NASA Astrobiology Institute.

The Carnegie Institution (www.CIW.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

The NASA Astrobiology Institute (NAI), founded in 1998, is a partnership between NASA, 16 U.S. teams, and five international consortia. NAI's goal is to promote, conduct, and lead interdisciplinary astrobiology research and to train a new generation of astrobiology researchers. For more information, see http://astrobiology.nasa.gov/nai.

Paul Butler | EurekAlert!
Further information:
http://www.ciw.edu

More articles from Physics and Astronomy:

nachricht From rocks in Colorado, evidence of a 'chaotic solar system'
23.02.2017 | University of Wisconsin-Madison

nachricht Prediction: More gas-giants will be found orbiting Sun-like stars
22.02.2017 | Carnegie Institution for Science

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>