Galaxy M51: nucleus of the Whirlpool Galaxy | 15/01/1995 | ||
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The NASA/ESA Hubble Space Telescope has snapped a view of several star generations in the central region of the Whirlpool Galaxy (M51), a spiral region 23 million light-years from Earth in the constellation Canes Venatici (the Hunting Dogs). The galaxy's massive center, the bright ball of light in the center of the photograph, is about 80 light-years across... | ||
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Image Credit: Nino Panagia (STScI and European Space Agency) and NASA | |||
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The
NASA/ESA Hubble Space Telescope has snapped a view of several star generations
in the central region of the Whirlpool Galaxy (M51), a spiral region 23
million light-years from Earth in the constellation Canes Venatici (the
Hunting Dogs).
The galaxy's massive center, the bright ball of light in the center of the photograph, is about 80 light-years across and has a brightness of about 100 million suns. Astronomers estimate that it is about 400 million years old and has a mass 40 million times larger than our Sun. The concentration of stars is about 5,000 times higher than in our solar neighborhood, the Milky Way Galaxy. We would see a continuously bright sky if we lived near the bright center. The dark "y" across the center is a sign of dust absorption. The bright dot in the middle of the "y" has a brightness of about one million suns, but a size of less than five light-years. Its power and its tiny size suggest that we have located the elusive central black hole that produces powerful radio jets. |
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Surrounding
the center is a much older stellar population that covers a region of about
1,500 light-years in diameter and is at least 8 billion years old, and may
be as old as the Universe itself, about 13 billion years.
Further away, there is a "necklace" of very young star-forming regions, clusters of infant stars, younger than 10 million years, which are about 700 light-years away from the center. Normally, young stars are found thousands of light-years away. Astronomers believe that stars in the central region were formed when a dwarf companion galaxy - which is not in the photograph - passed close to it, about 400 million years ago, stirring up dust and material for new star birth. The close encounter has been felt for a long time and is believed to be responsible also for the unusually high star formation activity in the bright necklace of young stars. |
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The colour image was assembled from four exposures taken Jan. 15, 1995 with Wide Field Planetary Camera-2 in blue, green, and red wavelengths. | Return to top of page |