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Ghez

the Milky Way

superimpose

Four times a year, Ghez focuses the telescope on the stars of the very heart of our Milky Way. She is looking for the telltale high speeds that reveal the presence of a black hole. The center of the Milky Way is so near and the Keck telescope so powerful Ghez is able to see closer into the center of the galaxy than anyone has ever done before.
Here's an example of one of the images we got just last night. The seeing was, this was kind of a typical night, not the best night, not the worst night. Each one of these blobs here is a star, and what you see is each star is distorted, that's what the atmosphere does. It's like looking through a pond, like if you want to look at a penny at the bottom of a pond and the water's moving. It looks all distorted. It looks different every time you look, so this is one exposure and the next exposure looks like this.
By superimposing thousands of these pictures taken overnight, the computer can compensate for the atmosphere's distortion producing a detailed picture of the centre of the galaxy.

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