Hubble's survey of planetary nebulae reveals surprisingly intricate, glowing patterns spun into space by aging stars: pinwheels, lawn sprinkler-style jets, elegant goblet shapes, and even some that look like a rocket engine's exhaust. These nebulae record the complex processes that happen in the final stages of a Sun-like star's evolution when it burns out and collapses to a white dwarf star. This is the Cat's Eye Nebula (NGC 6543), one of the first to be discovered. Credit: Hubble Heritage Team
Eerie, dramatic pictures from the Hubble show newborn stars emerging from dense, compact pockets of interstellar gas called evaporating gaseous globules (EGGs) that lie in the Eagle Nebula, a nearby star-forming region 7,000 light-years from Earth in the constellation Serpens. The columns--dubbed 'elephant trunks'--protrude from the wall of a vast cloud of molecular hydrogen like stalagmites rising above the floor of a cavern. Inside the gaseous towers, which are light-years long, the interstellar gas is dense enough to collapse under its own weight, forming young stars that continue to grow as they accumulate more and more mass from their surroundings. Credit: Jeff Hester (Arizona State University)
A 3-light-year-long pillar in the Carina Nebula photographed in visible light is bathed in the glow of light from hot, massive stars. Scorching radiation and fast winds (streams of changed particles) from these stars are sculpting the pillar and causing new stars to form within it. Streamers of gas and dust can be seen flowing off the top of the structure. The fledgling stars inside the pillar cannot be seen because they are hidden by gas and dust. Although the stars themselves are invisible, one of them is providing evidence of its existence: Thin puffs of material can be seen traveling to the left and to the right of a dark notch in the center of the pillar. The matter is part of a jet produced by a young star. Farther away, on the left, the jet is visible as a grouping of small, wispy clouds. The jet's total length is about 10 light-years.
The Sombrero Galaxy (M104) is a brilliant white, bulbous core encircled by the thick dust lanes that make up its spiral structure. As seen from Earth, the galaxy is titled nearly edge on: We view it from just 6 degrees north of its equatorial plane. At a relatively bright magnitude of +8, M104 is just beyond the limit of naked-eye visibility and is easily seen through small telescopes. The Sombrero lies at the southern edge of the rich Virgo cluster of galaxies and is one of the most massive objects in that group, equivalent to 800 billion suns. The galaxy is 50,000 light-years across and is 28 million light-years from the Earth.
This is the sharpest image taken of the merging Antennae galaxies. During the course of collision, billions of stars are formed. The brightest and most compact of these star-birth regions are called super star clusters. The two spiral galaxies started their interaction a few hundred million years ago, making the Antennae galaxies one of the nearest and youngest examples of a pair of colliding galaxies. Nearly half of the faint objects in the Antennae image are young clusters containing tens of thousands of stars. The orange blobs to the left and right of center are the two cores of the original galaxies and consist mainly of old stars crisscrossed by filaments of dust, which appear brown in the image. The two galaxies are dotted with brilliant blue star-forming regions surrounded by glowing hydrogen gas, appearing in the image in pink.
Hubble: A Journey Through Space and Time by Edward J. Weiler
Posts
No comments:
Post a Comment