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Birthday · August 18, 1998

APM 08279+5255: The Brightest Object Yet Known

August 18, 1998

You were not dropped into the cosmos as a stranger. You came from it entirely: borrowed from stars, carried by Earth, warmed by the Sun, and...

APM 08279+5255: The Brightest Object Yet Known

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APOD published August 18, 1998. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.

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APM 08279+5255: The Brightest Object Yet Known

Original APOD · August 18, 1998

It shines with the brightness of 100 billion Suns. Is it a mirage? The recently discovered quasar labeled APM 08279+5255 has set a new record as being the brightest continuously emitting object yet known. APM 08279+5255's great distance, though, makes it only appear as bright as magnitude 15.2, an object which can be seen with a moderate sized telescope. It is the quasar's extreme redshift of 3.87 that places it far across our universe, and implies a truly impressive energy output. One possible explanation of APM 08279+5255's record luminosity is that it is partly a mirage: its light is highly magnified by an intervening galaxy that acts as a gravitational lens. Alternatively, APM 08279+5255 might be the most active known center of an intriguing class of colliding galaxies rich in gas and dust.

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