The
Birth of StarsThe
Birth of Stars
The page you are
viewing is taken from an exhibit called MIRA: Exploring the Universe from the Central
Coast. |
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The most important instrument used by astronomers to study these regions is the spectrograph, a device that disperses the light of stars (the horizontal streaks in the image) so that the intensity of the star’s light at different wavelengths can be studied. The arrows indicate newly discovered T Tauri stars. (Photo courtesy of Bruce Weaver) | From our human perspective, it may seem that the stars are eternal. Unlike the planets, which the Greeks called "wanderers" because they appear in different parts of the sky in different seasons, the stars seem to be fixed forever in the same positions relative to one another. Only rarely does a naked-eye nova (literally, "new star") or supernova demonstrate that change occurs among the stars. But the apparent permanence of the stars is an illusion. The truth is that stars lead very dynamic existences: they are "born," grow to maturity, and finally die, sometimes violently. Deducing from our earthbound observation point how stars are created, how they shine, and what happens to them over the span of their existence is one of the great detective stories of modern science. The study of very young stars has long been a MIRA specialty. Stars belonging to the class known as T Tauri are very young (not even 10 million years old!) and are still in the process of formation. They demonstrate youthful exuberance, varying in brightness and emitting X-rays and infrared radiation. Our Sun was once a T Tauri star, until it settled down (thankfully for us!) to its current staid middle age. T Tauri and other stars are born in Star Formation Regions (SFR) like the two pictured on the light boxes to the left and right. In these two areas of the constellation Orion, we can see the gas and dust that are the raw materials from which stars are created. The famous Orion Nebula is one of the most beautiful objects in the night sky. The bright glow in the center of the nebula comes from a cluster of very young, hot stars that have recently coalesced from the gas and dust of the nebula. The Horsehead Nebula is an area of star formation that is the object of a current MIRA research project. The red color of much of this area comes from hydrogen gas, the most plentiful element in the universe and the principal ingredient of stars. The gas glows red because it has been heated by strong UV radiation from hot young stars. Many of the fainter stars in this nebula are T Tauri stars. |
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Here is the spectrum of the prototype of the T Tauri star class, T Tauri. The pattern of peaks, due to hydrogen and sulphur atoms, are telltale signatures of this class of star. (MIRA spectrum) | |
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The material from which T Tauri stars coalesce is also the site of planet formation, so when we study this fascinating class of stars, we are in effect looking at our own origin. (Painting by Beth Avery) | |
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| Last updated February 22, 2001 by et. | ||
