‘First light’ from any new telescope is an exciting moment, but never more so than with the Kepler instrument. Dust cover off, the space-based telescope is now looking at its target, a starfield in the Cygnus-Lyra region of the Milky Way. Kepler’s full field of view covers a 100-degree swath of sky, containing scenery like NGC 6791, an eight-billion year old cluster some 13,000 light years from us, as seen in the image below.

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Image: The area pictured is 0.2 percent of Kepler’s full field of view, and shows hundreds of stars in the constellation Lyra. The image has been color-coded so that brighter stars appear white, and fainter stars, red. It is a 60-second exposure, taken on April 8, 2009, one day after the spacecraft’s dust cover was jettisoned. Credit: NASA/JPL-Caltech.

Loosely bound, the stars in NGC 6791 have begun to spread out from each other, the signature of what is called an ‘open cluster.’ The view is impressive but also blurry, an intentional effect that is being used, as this NASA news release points out, to keep the brightest stars from overloading the individual pixels in the spacecraft’s detectors. You’ll see the same blurry effect in the second image, which centers on a star known to have at least one planet orbiting around it. TrES-2 is a ‘hot Jupiter’ that makes its way around its host every 2.5 days.

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Image: Here we see an area one-thousandth of Kepler’s full field of view, showing hundreds of stars at the very edge of the constellation Cygnus. The image has been color-coded like the one above. Note the star orbited by TrES-2 in the center of the image. Credit: NASA/JPL-Caltech.

It’s interesting how our methods have come together in this second image. TrES-2 was detected by the Trans-Atlantic Exoplanet Survey, which uses 4-inch Schmidt telescopes equipped with CCD cameras (located at Palomar, Lowell Observatory and the Canary Islands) to run automated search routines. This humble instrumentation was able to snare the transit of a Jupiter-like planet across a star some 750 light years from Earth. The Keck Observatory confirmed the discovery, which will now be examined by a space telescope capable of seeing much smaller worlds.

TrES-2 thus offers an early tune-up for Kepler’s instrumentation as well as an early target for further science. We’re about to embark on a three and a half year project to sample light from 100,000 stars, a study that will vastly expand our existing catalog of exoplanets and give us our earliest sense of how common small worlds in the habitable zone of their stars are. With a 95-megapixel camera able to detect changes in brightness of 20 parts per million, Kepler will be ready to go as soon as the necessary calibration of its photometer and subsequent alignment is completed. Figure just a few more weeks before Kepler’s hunt begins in earnest.