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Posts Tagged ‘solar systems’

Solar System’s Youth Gives Clues To Planet Search


Disk isotopes modeling results. Image courtesy of Alan Boss

Disk isotopes modeling results. Image courtesy of Alan Boss

Comets and meteorites contain clues to our solar system’s earliest days. But some of the findings are puzzle pieces that don’t seem to fit well together. A new set of theoretical models from Carnegie’s Alan Boss shows how an outburst event in the Sun’s formative years could explain some of this disparate evidence. His work could have implications for the hunt for habitable planets outside of our solar system. It is published by The Astrophysical Journal.

One way to study the solar system’s formative period is to look for samples of small crystalline particles that were formed at high temperatures but now exist in icy comets. Another is to analyze the traces of isotopes—versions of elements with the same number of protons, but a different number of neutrons—found in primitive meteorites. These isotopes decay and turn into different, so-called daughter, elements. The initial abundances of these isotopes tell researchers where the isotopes may have come from, and can give clues as to how they traveled around the early solar system.

Stars are surrounded by disks of rotating gas during the early stages of their lives. Observations of young stars that still have these gas disks demonstrate that sun-like stars undergo periodic bursts, lasting about 100 years each, during which mass is transferred from the disk to the young star.

Full Story: https://carnegiescience.edu/news/solar_system%E2%80%99s_youth_gives_clues_planet_search

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Early Universe To Be Revealed


Solar storms, space junk and the formation of the Universe are about to be seen in an entirely new way with the start of operations today by the $51 million Murchison Widefield Array (MWA) radio telescope.

The first of three international precursors to the $2 billion Square Kilometre Array (SKA) telescope, the MWA is located in a remote pocket of outback Western Australia. It is the result of an international project led by Curtin University and was officially turned on this morning by Australia’s Science and Research Minister, Senator Kim Carr.

Using bleeding edge technology, the MWA will become an eye on the sky, acting as an early warning system that will potentially help to save billions of dollars as it steps up observations of the Sun to detect and monitor massive solar storms. It will also investigate a unique concept which will see stray FM radio signals used to track dangerous space debris.

Full Story: http://www.icrar.org/news/news_items/early-universe-to-be-revealed

Cosmic Dust Belts Without Dust


Planets and asteroids, red giants and brown dwarfs – there are all kinds of objects in our Universe. Debris disks are among them. These are belts consisting of countless dust particles and planetesimals, circling around one central star. “At least one fifth of stars are surrounded by dust belts like these,” Prof. Dr. Alexander Krivov from the Friedrich-Schiller-University Jena explains. “They are the remains of the formation of planets, in which the unused, building materials are collected,” the astrophysicist points out. Therefore debris disks are an important piece in the puzzle to be able to better understand the variety of planetary systems.

For astronomers like Alexander Krivov debris disks are actually nothing new. Our sun is also orbited by such dust belts: the Asteroid Belt and the Kuiper Belt with Pluto being perhaps the most well-known object in it. However, the Jena astrophysicist, accompanied by an international team of scientists, has observed six stars similar to the sun with extraordinary dust belts: The newly discovered debris disks are not only bigger than the Kuiper Belt. Above all they are extremely cold. With a temperature of about minus 250 °C they are the coldest debris disks known so far. The scientists report on it in the science journal ‘The Astrophysical Journal’, which is already online and will be available in a print version from 20 July. “We were surprised that such cold debris disks exist at all,” Alexander Krivov, the lead author of the new study, says. By way of comparison: The Kuiper Belt is about 70 °C degree warmer, some of the dust disks even reach room temperature.

Full Story: http://www.uni-jena.de/en/News/PM130708_krivov_debris_disks.html

NASA’s Voyager 1 Explores Final Frontier Of Our ‘Solar Bubble’

July 2, 2013 1 comment

Artist's concept. Image Credit: NASA/JPL-Caltech

Artist’s concept. Image Credit: NASA/JPL-Caltech

Data from Voyager 1, now more than 11 billion miles (18 billion kilometers) from the sun, suggest the spacecraft is closer to becoming the first human-made object to reach interstellar space.

Scientists have seen two of the three signs of interstellar arrival they expected to see: charged particles disappearing as they zoom out along the solar magnetic field, and cosmic rays from far outside zooming in. Scientists have not yet seen the third sign, an abrupt change in the direction of the magnetic field, which would indicate the presence of the interstellar magnetic field.

“This strange, last region before interstellar space is coming into focus, thanks to Voyager 1, humankind’s most distant scout,” said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. “If you looked at the cosmic ray and energetic particle data in isolation, you might think Voyager had reached interstellar space, but the team feels Voyager 1 has not yet gotten there because we are still within the domain of the sun’s magnetic field.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-209
Also: http://www.jhuapl.edu/newscenter/pressreleases/2013/130627.asp

Wide Binary Stars Can Wreak Havoc In Planetary Systems

January 9, 2013 Leave a comment

An international team of astrophysicists has shown that planetary systems with very distant binary stars are particularly susceptible to violent disruptions, more so than if the systems had two stellar companions with tighter orbits around each other.

The team, led by Northwestern University’s Nathan Kaib, conducted 3,000 computer simulations to study the effects of binary stellar companions (some with tight orbits around each other and others with wide or distant orbits) on the formation and evolution of planetary systems.

The researchers found that wide binary stars in planetary systems can lead to dramatic events over time. In one hypothetical system, the researchers added a wide binary companion to the Earth’s solar system. This triggered at least one of four giant planets (Jupiter, Saturn, Uranus and Neptune) to be ejected in almost half of the simulations.

Full Story: http://www.northwestern.edu/newscenter/stories/2013/01/wide-binary-stars-can-wreak-havoc-in-planetary-systems.html

Astronomers Discover And “Weigh” Infant Solar System

December 8, 2012 Leave a comment

Astronomers have found the youngest still-forming solar system yet seen, an infant star surrounded by a swirling disk of dust and gas more than 450 light-years from Earth in the constellation Taurus.

The star currently has about one-fifth the mass of the Sun, but, the scientists say, will likely pull in material from its surroundings to eventually match the Sun’s mass. The disk surrounding the young star contains at least enough mass to make seven Jupiters, the largest planet in our Solar System.

“This very young object has all the elements of a solar system in the making,” said John Tobin, of the National Radio Astronomy Observatory. Tobin and his colleagues used the Submillimeter Array and the Combined Array for Millimeter-wave Astronomy to study the object, called L1527 IRS, residing in a stellar nursery called the Taurus Cloud.

Full Story: http://www.nrao.edu/pr/2012/youngsystem/

Voyager Observes Magnetic Field Fluctuations In Heliosheath

October 29, 2012 Leave a comment

As they near the outer reaches of the solar system, for the past several years the two Voyager spacecraft have been sending back observations that challenge scientists’ views of the physics at the edge of the heliosphere, the bubble created by charged particles flowing outward from the Sun. A new study looks at magnetic field fluctuations and cosmic ray intensity observed by Voyager I.

In 2004, Voyager I crossed the termination shock, the region where the solar wind begins to slow as it interacts with the interstellar medium. Just outside the termination shock is the heliosheath, where the solar wind continues to slow, reaching a stagnation region where solar wind speed drops to zero. Burlaga and Ness studied the magnetic field observed by Voyager I during 2010, when the spacecraft was moving through this stagnation region. Their analysis shows that magnetic field fluctuations outside the termination shock were primarily compressive fluctuations in field strength along the direction of the motion of the planets around the Sun. The fluctuations were observed on time scales of several hours.

Full Story: http://www.agu.org/news/press/jhighlight_archives/2012/2012-10-29.shtml#one