Latest Circumstellar discs Stories
Astronomers from McMaster University in Hamilton, Ontario find that "dead zones"- which typically extend out to 13 astronomical units from the central star of an extrasolar planetary system - can significantly slow planetary migration so that planets are not lost to the systems. This release summarizes work to be described in a press conference at the American Astronomical Society meeting in Calgary, Alberta on June 5, 2006, and in an invited talk at a scientific session during the...
By Deborah ZabarenkoWASHINGTON -- Planets outside our solar system might form, phoenix-like, out of the debris circling a dead star known as a pulsar, researchers reported on Wednesday after finding the makings for a planet near such a body.This could mean that planet-formation could be more common than previously thought, said Deepto Chakrabarty of the Massachusetts Institute of Technology."What's remarkable here is this process of planet formation, which we associate with the birth of...
By Deborah ZabarenkoWASHINGTON (Reuters) - Planets outside our solar system might form, phoenix-like, out of the debris circling a dead star known as a pulsar, researchers reported on Wednesday after finding the makings for a planet near such a body.This could mean that planet-formation could be more common than previously thought, said Deepto Chakrabarty of the Massachusetts Institute of Technology."What's remarkable here is this process of planet formation, which we associate with the...
NASA's Spitzer Space Telescope has uncovered new evidence that planets might rise up out of a dead star's ashes. The infrared telescope surveyed the scene around a pulsar, the remnant of an exploded star, and found a surrounding disk made up of debris shot out during the star's death throes. The dusty rubble in this disk might ultimately stick together to form planets. This is the first time scientists have detected planet-building materials around a star that died in a fiery blast....
JAA -- In an article to be published in Astronomy & Astrophysics, two British astronomers present new numerical simulations of how planetary systems form. They find that, in the early stages of planetary formation, giant protoplanets migrate inward in lockstep into the central star. The current picture of how planetary systems form is as follows: i) dust grains coagulate to form planetesimals of up to 1 km in diameter; ii) the runaway growth of planetesimals leads to the formation of...
AAAS -- In the search for life on other worlds, scientists can listen for radio transmissions from stellar neighborhoods where intelligent civilizations might lurk or they can try to actually spot planets like our own in habitable zones around nearby stars. Either approach is tricky and relies on choosing the right targets for scrutiny out of the many thousands of nearby stars in our galactic neighborhood. Margaret Turnbull, an astronomer at the Carnegie Institution of Washington, has devoted...
NASA -- These two bright debris disks of ice and dust appear to be the equivalent of our own solar system's Kuiper Belt, a ring of icy rocks outside the orbit of Neptune and the source of short-period comets. The disks encircle the types of stars around which there could be habitable zones and planets for life to develop. The disks seem to have a central area cleared of debris, perhaps by planets.The new disks, each about 60 light-years from Earth, bring to nine the number of dusty debris...
Washington DC -- New theoretical work shows that gas-giant planet formation can occur around binary stars in much the same way that it occurs around single stars like the Sun. The work is presented today by Dr. Alan Boss of the Carnegie Institution's Department of Terrestrial Magnetism (DTM) at the American Astronomical Society meeting in Washington, DC. The results suggest that gas-giant planets, like Jupiter, and habitable Earth-like planets could be more prevalent than previously thought....
WASHINGTON, D. C. -- New observations of the Orion Nebula at infrared wavelengths reveal that small dust grains located in disks around young stars are growing, taking the initial steps toward forming planets despite bathing in a flood of radiation from highly luminous stars. The properties of dust in disks around young stars plays a pivotal role in understanding star formation and determining the origins of planets in our Solar system and in extrasolar planetary systems as well. The results...
NASA -- Astronomers have found a debris disk around a sun-like star that may be forming or has formed its terrestrial planets. The disk - a probable analog to our asteroid belt - may have begun a solar-system-scale demolition derby, where the rocky remains of failed planets collide chaotically. "This is one of a very rare class of objects that may give us a glimpse into what our solar system may have looked like during the formation of our terrestrial planets," said Dean C. Hines of...
Latest Circumstellar discs Reference Libraries
Cosmogony -- Cosmogony is the study of the origins of celestial objects. It is most commonly used to refer to the study of the origin of the solar system. Currently, the most widely accepted theory is that the solar system was formed roughly 5 billion years ago with the collapse of a nebula of gas and dust, likely caused by shock waves generated by a nearby supernova. The solar system would have formed as a member of a star cluster, now long-since dispersed throughout the Milky Way...
Asteroid Belt -- The Asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. It is believed that, during the first million years of the solar system history, planets formed by accretion of planetesimals. Ripetute collisions led to the familiar rocky planets and to the gas giant's cores. However, in this zone of the system the strong gravity of Jupiter inhibited the final stages...
Vega -- Vega (Alpha Lyrae) is the lead star in the constellation Lyra, reaching near directly overhead the mid-northern latitudes, during the summer. It's a "nearby star" at only 25 light years distant and together with Arcturus and Sirius, one of the brightest stars in the Sun's neighbourhood. Vega is a vertex of the Summer Triangle. Its spectral class is A0V (Sirius, an A1V, is slightly less powerful) and it's firmly in the main sequence, fusing hydrogen to helium in its core....
Epsilon Eridani -- Epsilon Eridani is a main-sequence star in the constellation of Eridanus (the river). It is often used in science fiction because it is extremely sunlike, and in the fictional Star Trek universe it is the home sun of the planet Vulcan which is home to Mr. Spock. It is the third closest star visible without a telescope. It has 85% of the Sun's mass, almost that much of its diameter, and 28% of its luminosity. It is 10.5 light years from Earth. Its spectrum is...
