Latest Circumstellar discs Stories
By Deborah Zabarenko WASHINGTON (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.
Astronomers have uncovered new evidence that planets might rise up out of a dead star's ashes. Spitzer surveyed the scene around a pulsar and found a surrounding disk made up of debris shot out during the star's death throes.
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.
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.
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.
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.
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.
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.
Astronomers using NASA's Spitzer Space Telescope have discovered a remarkably small brown dwarf surrounded by a dusty disk. The brown dwarf contains only about 8 times the mass of Jupiter.
Brown dwarfs, like more massive normal stars, are formed when interstellar gas and dust clouds collapse. When this happens, a central, dense area builds up, embedded in a rotating disc made of gas and dust. These circumstellar discs produce infrared radiation according to their temperature.
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 over...
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...
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