An international team of astronomers has discovered a fourth giant planet, HR 8799e, outside our solar system. The new planet joins the three planets that were the subjects of the first-ever images of a planetary family orbiting a star other than our Sun. The planets orbit the star HR 8799, which lies about 129 light years from Earth and is faintly visible to the naked eye.
The international team included astronomer Dr. Christian Marois of the National Research Council Canada (NRC) in Victoria, B.C., as well as astronomers from the University of California Los Angeles (UCLA), Lawrence Livermore National Laboratory (LLNL), and the Lowell Observatory. Their discovery was published today in Nature (http://dx.doi.org/10.1038/nature09684), and images of the fourth planet were captured at Hawaii's W. M. Keck Observatory.
All four planets orbiting HR 8799 are similar in size: likely between five and seven times the mass of Jupiter, the largest planet in the Sun's own family. The newly revealed planet orbits HR 8799 more closely than the other three. If this newly discovered planet were in orbit around the Sun, it would lie between the orbits of Saturn and Uranus.
"We reached a milestone in the search for other worlds in 2008 with the discovery of the HR 8799 planetary system," said Dr. Christian Marois, an astronomer with NRC. Dr. Marois is the first author of the new paper and designed the improved image-processing software that made the new discovery possible. "The images of this new inner planet are the culmination of ten years' worth of innovation, making steady progress to optimize every aspect of observation and analysis. Compared with what was previously possible, this allows us to detect planets located ever closer to their stars and ever further from our own solar system."
Discovery of this fourth giant planet strengthens the remarkable resemblance between the HR 8799 planetary system and our own — the HR 8799 system appears as a supersized version of our solar system. "Besides having four giant planets, both systems also contain two 'debris belts,' composed of small rocky or icy objects along with lots of tiny dust particles," said co-author Ben Zuckerman, a professor of physics and astronomy at UCLA. The mass of the HR 8799 planetary system is much more extreme than that of our own — the combined mass of the four giant planets may be twenty times higher, and the debris belt counterparts are also much larger than our own.
"The four massive planets pull on each other gravitationally," said co-author Quinn Konopacky, a post-doctoral researcher at LLNL. "We don't yet know if the system will last for billions of years, or fall apart in a few million more. As astronomers carefully follow the HR 8799 planets during the coming decades, the question of the stability of their orbits could become much clearer."
The origin of these four giant planets remains a puzzle — neither of the two main models of planet formation can account for all four objects. Dr. Bruce Macintosh of LLNL, a co-author, noted that there's no simple model that can form all four planets at their current location. It's going to be a challenge for our theoretical colleagues.
Travis Barman, a Lowell Observatory exoplanet theorist and study co-author stated images like these bring the exoplanet field, which studies planets outside our solar system, into an era of exoplanet characterization. Astronomers can now directly examine the atmospheric properties of four giant exoplanets that are all the same young age and that formed from the same building materials.
Detailed study of the properties of HR 8799e will be challenging due to its relative faintness and proximity to its star. To overcome these limitations, a team led by Dr. Macintosh, including NRC and several US institutions, is building an advanced new instrument, called the Gemini Planet Imager for the Gemini Observatory. This new instrument will physically block the starlight and allow quick detection and detailed characterization of planets similar to HR 8799e. The Gemini Planet Imager is scheduled to arrive at the Gemini South telescope in Chile late in 2011. "We can expect a tidal wave of new discoveries with the new planet imager. HR 8799 is really just the beginning, the tip of the iceberg," said Dr. Marois.For more information or to arrange an interview with Dr. Marois, please visit NRC's Web site at http://www.nrc-cnrc.gc.ca or contact:
NRC Media Relations | EurekAlert!
Magnetic nano-imaging on a table top
20.04.2018 | Georg-August-Universität Göttingen
New record on squeezing light to one atom: Atomic Lego guides light below one nanometer
20.04.2018 | ICFO-The Institute of Photonic Sciences
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy