The Kepler space telescope has taken its first images of the region near the constellation Cygnus which it will scour for planets for at least the next 3 years.

The telescope, which was launched in early March, is designed to observe the same wide field of stars continuously for the length of its mission, providing astronomers with a record of the changes in brightness of 100,000 stars (See: Looking for worlds like this one).

The team selected those stars from the 4.5 million in the telescope’s unusually large field of view because they are the likeliest planet hosts based on their size and composition. A narrower field of view might have allowed the astronomers to see more details or stars further away, but Kepler’s primary mission is to survey stars for regular slight dips in their brightness, a sign that an orbiting planet is blocking the star’s light. Astronomers routinely use small, wide-field telescopes on Earth to detect such dips and find Jupiter-sized planets around other stars, but to enable Kepler to find the even smaller dip from an Earth-sized planet they have launched it above the Earth’s atmosphere.

Full images below the fold.

This amateur image by Carter Roberts indicates the location of Kepler’s hunting ground in the sky:

And here’s the first image, with star cluster NGC 6971 and the known planet-hosting star TrES-2 circled:

Here’s a close-up of the TrES-2 region. Since astronomers are interested in comparing the changes in the light coming from a given star, they wiggle the telescope to spill light from each star onto several pixels, preventing any one pixel from saturating with too much light.

Photos: Carter Roberts / Eastbay Astronomical Society, NASA/JPL-Caltech, NASA/JPL-Caltech