Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2002 April 11
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Antennae Galaxies in Near-Infrared
Credit: Bernhard Brandl and the WIRC team (Cornell), Palomar Observatory

Explanation: What happens when galaxies collide? One of the best studied examples of the jumble of star clusters, gas, and dust clouds produced by such a cosmic train wreck is the interacting galaxy pair NGC 4038 / NGC 4039, the Antennae Galaxies, only sixty million light-years away. In visible light images, long, luminous tendrils of material seem to reach out from the galactic wreckage, lending the entwined pair an insect-like appearance. But this penetrating view from the new Wide-field InfraRed Camera (WIRC) attached to the Palomar Observatory's 200 inch Hale telescope shows, in false-color, details of some otherwise hidden features. The large central nuclei of the two original galaxies dominate the near-infrared scene speckled with other bright sources which are themselves giant, newly formed star clusters. Remarkably the northern (topmost) nucleus, obscured in optical images, is also revealed here to have a barred, mini-spiral structure reminiscent of many "single" spiral galaxies.

Tomorrow's picture: comet check

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
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