New stars are surrounded by rotating gas disks during the early stages of their lives. Gas giant planets are thought to form in the presence of these disks.
Observations of young stars that still have these gas disks demonstrate that sun-like stars undergo periodic outbursts, lasting about 100 years, which transfer mass from the disk onto the young star, increasing its luminosity. It is thought that these short bursts of mass accretion are driven by marginal gravitational instability in the gas disk.
There are competing theories for how gas giant planets form around proto-suns. One proposes that the planets formed from slowly growing ice and rock cores, followed by rapid accretion of gas from the surrounding disk. The other theory proposes that clumps of dense gas form in spiral arms, increasing in mass and density, forming a gas giant planet in a single step.
Boss developed highly detailed, three dimensional models demonstrating that regardless of how gas giant planets form, they should have been able to survive periodic outbursts of mass transfer from the gas disk onto the young star. One model similar to our own Solar System was stable for more than 1,000 years, while another model containing planets similar to our Jupiter and Saturn was stable for more than 3,800 years. The models showed that these planets were able to avoid being forced to migrate inward to be swallowed by the growing proto-sun, or being tossed completely out of the planetary system by close encounters with each other.
"Gas giant planets, once formed, can be hard to destroy," said Boss, "even during the energetic outbursts that young stars experience."
Given that searches for extrasolar gas giant planets have found them to be present around about 20% of sun-like stars, this is a reassuring outcome. It suggests that our improved theoretical understanding of the formation and orbital evolution of gas giants is on the right track.
This research was supported in part by the NASA Origins of Solar Systems Program and contributed to in part to the NASA Astrobiology Institute. The calculations were performed on the Carnegie Alpha Cluster, the purchase of which was partially supported by a NSF Major Research Instrumentation grant.
The Carnegie Institution for Science is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
Alan Boss | EurekAlert!
Sharpening the X-ray view of the nanocosm
23.03.2018 | Changchun Institute of Optics, Fine Mechanics and Physics
Drug or duplicate?
23.03.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy