August 24, 2008
Billions of years of cosmic evolution — the birth and death of stars, the slow coalescence of planets, the patient unfolding of life — all...
Grand Spiral Galaxy NGC 1232
Birthday · August 24, 2008
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APOD published August 24, 2008. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232, captured in detail by one of the new Very Large Telescopes, is a good example. The visible is dominated by millions of bright stars and dark dust, caught up in a gravitational swirl of spiral arms revolving about the center. Open clusters containing bright blue stars can be seen sprinkled along these spiral arms, while dark lanes of dense interstellar dust can be seen sprinkled between them. Less visible, but detectable, are billions of dim normal stars and vast tracts of interstellar gas, together wielding such high mass that they dominate the dynamics of the inner galaxy. Invisible are even greater amounts of matter in a form we don't yet know - pervasive dark matter needed to explain the motions of the visible in the outer galaxy. What's out there? Announcement: APOD Editor RJN to open Final Frontier art exhibit in Ireland on August 28