December 11, 1996
The Earth has carried you around the Sun again, steady as ever, while the stars kept their patient watch.
Starburst Ring in Galaxy NGC 1317 Credit:
Birthday · December 11, 1996
A little universe, just for you
Your date.
Ready to give.
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APOD published December 11, 1996. Full image credits are on the original APOD entry below. A publication-date match, not a photo taken on your date. Independent of NASA.
Where do stars form? A typical place is an area of dense nebular gas common to arms in spiral galaxies. Sometimes, however, a burst of star formation can occur with unusual geometry. Nearby galaxy NGC 1317 shows such an unusual ring of star formation surrounding its barred nucleus. In the above image, older stars appear more red and are more evident in the leftmost photograph in visible light. The rightmost photograph taken by the Ultraviolet Imaging Telescope is in ultraviolet and highlights stars which are younger and bluer and shows the starbirth ring. This unusual ring may be evidence of a gravitational encounter with another galaxy, causing a density wave to ripple out from the galaxy's center.