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Creating a Planetary Nebula
Space Telescope Science Institute
Video: 3 MB, Quicktime MOV
Sun-like stars reach the end of their lives after they have consumed most of the hydrogen in their cores. They enter the red giant phase of their life, and eventually collapse into a white dwarf. During this transition, these stars often eject a shell of thin matter that forms a planetary nebula. These are some of the most beautiful and unusual looking objects in the Universe. Many show symmetric lobes like an hourglass which form at the poles of the star.
How do planetary nebulae form?
This movie combines scientific images with an artist's imagination, showing one possible mechanism for the formation of these types of planetary nebulae. A key clue comes from the gas flowing out from the center of the nebula. The gas is ejected in what astronomers call jets
at over 700,000 miles per hour (1.1 million kilometers per hour). From telescopic observations, we also know that the central star in some of these nebulae is one of a very closely orbiting pair; one star may even be engulfed by the other's gaseous stellar atmosphere.
Forming jets
Astronomers theorize that the gravity of one star pulls some of the gas from the surface of the other and funnels it into a thin, dense disk extending into space. The disk acts like a nozzle, pushing the stellar wind into the jets. This is similar to the process that takes place in a jet engine on a commercial airliner.
Gordon Myers
Evolution of a Star Cluster
Simon Portegies Zwart (University of Amsterdam), Frank Summers (STScI)
Star clusters come in two general types: open clusters, which usually contain a few hundred stars at most, and globular clusters, which have many thousands of stars. How do star clusters change over time? This movie shows that the gravity that stars exert upon each other in a cluster cause them to dance, bob, and weave in beautiful and frenetic orbits. Indeed, the center of a globular cluster resembles a busy beehive, filled with dynamic activity.
Video: 5 MB, MPEG
The simulation
This visualization presents a globular cluster composed of 6,144 stars. The width of the frame represents more than a hundred trillion miles. As the movie unfolds, the evolution of the cluster is shown in this time-lapse movie, in which each second represents thousands of years passing by! As the stars orbit one other, several stars are ejected from the cluster through close gravitational encounters with more massive stars. The stars are shown in a scientific approximation of what the human eye would see: each star's brightness depends both on its intrinsic brightness and on its distance away from the virtual camera,
while each star's color is only slightly exaggerated. These calculations were made with the GRAPE-4, one of the fastest special-purpose supercomputers in the world.
Forming jets
Astronomers theorize that the gravity of one star pulls some of the gas from the surface of the other and funnels it into a thin, dense disk extending into space. The disk acts like a nozzle, pushing the stellar wind into the jets. This is similar to the process that takes place in a jet engine on a commercial airliner.
Charles Liu
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The Formation of Stars
Melania Brolis (Osservatorio Astronomico)
Stars form in interstellar clouds of gas and dust, trillions of miles across. When the random motions of the gas cause a small part of the cloud to become denser than the rest of the cloud, gas begins to collapse, contract, and heat up. At temperatures of millions of degrees, nuclear fusion begins at the center of the gas clump and a star is born. In some clouds, dozens or hundreds of stars form together creating a star cluster. This movie shows images, taken with various telescopes, of one star that has formed in the Orion Nebula star cluster.
Video: 634 kB, MPEG
Star formation
The movie takes us on a journey from the night sky to the Orion Nebula, a star forming region at the belt of the constellation Orion. Each image in the sequence reveals more detail, as seen by the Hubble Space Telescope. Near the final image, we see newly hatched stars swaddled in teardrop-shaped cocoons of gas called proplyds.
These are the remnants of the protostellar gas clouds that collapsed to form these new stars. Finally, we look closely at a new star, not quite as bright as our own Sun, with what appears to be a dark, gaseous protoplanetary disk around it. Could this be a new solar system being born?
Forming jets
Astronomers theorize that the gravity of one star pulls some of the gas from the surface of the other and funnels it into a thin, dense disk extending into space. The disk acts like a nozzle, pushing the stellar wind into the jets. This is similar to the process that takes place in a jet engine on a commercial airliner.
Austin Reiter
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