Vast wisps of gas and dust and scores of newborn stars glow brilliantly in this close-up view of a portion of the Orion Nebula, a stellar nursery that's about 1,500 light-years from Earth, from Hubble Space Telescope. It has already given birth to thousands of stars, with many more still taking shape. Much of the nebula is illuminated by a few hot, bright, massive stars at its center. Radiation from these stars also evaporates much of the surrounding material, shutting off star formation in the nebula's inner precincts. This image includes a detailed view of LL Orionis, a bright star at lower left, that is still in the process of forming. Its radiation and winds have cleared a small cocoon around the hot star. The Orion Nebula is bright enough to see with the unaided eye, beneath Orion's Belt. [NASA/ESA/Hubble Heritage Team]
One of the most remarkable astronomical objects that’s visible to the unaided eye is at its best on winter evenings. The Orion Nebula is in the southeast as darkness falls tonight, to the lower right of Orion’s well-known belt.
To the eye alone, the nebula looks like a big but faint star. But its true nature is far more impressive. Instead of a single star, it’s a stellar nursery — a light-years-wide complex of gas and dust that’s given birth to thousands of stars.
Many of the stars are less than a million years old, with some just a few tens of thousands of years old. Some of the youngest are also the hottest and most massive. Strong “winds” from these stars compress some of the nearby clumps of gas, causing them to collapse and form new stars. But the winds also blow away some of the gas and dust, preventing stars from taking shape.
In addition to the big boys, the nebula also contains thousands of smaller, fainter stars, plus the “failed stars” known as brown dwarfs. And many of the stars are encircled by disks of gas and dust — the raw materials for planets.
And there’s plenty of gas and dust for making more stars — giant clouds and streamers that can stretch across light-years. Some of them glow like fluorescent bulbs, energized by the radiation from hot stars, while others reflect the light from the nebula’s crowded stars. They fill the skies of these stars with light and color — the remarkable glow of a busy stellar nursery.
Script by Damond Benningfield, Copyright 2013
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