Today's announcement of the discovery of the two planets, Kepler 9b and 9c, is based on seven months of observations of more than 156,000 stars being monitored for subtle brightness changes as part of an ongoing search for Earth-like planets outside our solar system. Scientists designated the sun-like star Kepler-9.
The inner world, Kepler 9-b, orbits its star every 19.2 days at a distance of 13 million miles, while the outer world orbits once in 38.9 days at a distance of 21 million miles. (In comparison, Mercury has an orbital period of 88 days.) They orbit nearly in resonance, with the inner planet completing two orbits for every one of the outer planet. Both are Saturn-sized gas giants, with the inner world weighing in at 0.25 Jupiter mass (80 Earths) while the outer world is a slimmer 0.17 Jupiter mass (54 Earths).
"This is the first confirmed system of more than one planet transiting the same star," said Matthew Holman, a Kepler Mission scientist from the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass. Scientists confirmed the multiple transits with radial velocity observations conducted at the W.M Keck Observatory in Hawaii.
Holman said systems with multiple transiting planets are particularly rich with information that provides clues as to the physical characteristics. Specifically, astronomers can measure how the time between successive transits changes from orbit to orbit due to mutual gravity between the two worlds. "We can actually see evidence of the gravitational interaction of these two planets through the deviations in their transit times," Holman said.
"This discovery is the first clear detection of transit timing variations," he added.
In addition to the two confirmed giant planets, Holman said Kepler scientists also identified an additional "super-Earth-size" transiting planet candidate that will need additional observations to confirm if it is indeed a planet or merely a false alarm. Current observations suggest that the planetary candidate might be about 1.5 times the size of Earth and orbits the star once every 1.6 days at a distance of only 2.5 million miles.
Kepler, a space-based observatory, looks for the signatures of planets by measuring tiny decreases in the brightness of stars when planets cross in front of, or transit them. The size of the planet can be derived from the change in the star's brightness. In June, mission scientists announced the mission has identified more than 700 planet candidates, including five systems with more than one planet candidate. This is the first of those systems to be confirmed.
The 28-member Kepler science team is using ground-based telescopes and the Hubble Space Telescope and Spitzer Space Telescope to perform follow-up observations on 400 of the planet candidates. The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these observations will determine which of the candidates can be identified as planets.
Without the additional information, candidates that are actual planets cannot be distinguished from false alarms, such as binary stars -- two stars that orbit each other. The size of the planetary candidates also can be only approximated until the size of the stars they orbit is determined from additional spectroscopic observations made by ground-based telescopes. In the case of Kepler-9, the planetary nature was first confirmed by the scale of the transit timing variations and was further verified by radial velocity measurements.
Kepler will continue conducting science operations until at least November 2012, searching for planets as small as Earth, including those that orbit stars in a warm habitable zone where liquid water could exist on the surface of the planet. Since transits of planets in the habitable zone of solar-like stars occur about once a year and require three transits for verification, it is expected to take at least three years to locate and verify an Earth-size planet.
This press release is being issued jointly with NASA.
Ames Research Center is responsible for the ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed the Kepler mission development. Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system, and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data.Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.
For more information, contact:David A. Aguilar
Christine Pulliam | EurekAlert!
Move over, lasers: Scientists can now create holograms from neutrons, too
21.10.2016 | National Institute of Standards and Technology (NIST)
Finding the lightest superdeformed triaxial atomic nucleus
20.10.2016 | The Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences