Kepler launched

Cables being attached to Kepler

Kepler has been successfully launched, and over the next three and a half years it will look at a single patch of sky in search of planets. The spacecraft is sensitive enough to detect the existence of planets even as small as our own puny planet, Earth. It does it by detecting the very slight dimming of starlight as a planet moves in front of its parent star. It also looks at many stars at once so that it astronomers would not have to pick a star at random, just hoping that the planet's orbital plane is at the right inclination and that the planet just passes in front of the star when Kepler is looking at it. With orbital periods of a year or more like our own Earth, keeping watch of many stars at once would have to be the way to go.

Image of planet around Sun-like star?

Sun-like star 1RSX J160929.1-210524 in the center and a possible planet at the upper left
Sun-like star 1RSX J160929.1-210524 in the center and a possible planet at the upper left

Canadian astronomers have used the Gemini North telescope at Hawaii to obtain what may be the first image of a planet orbiting another star similar to our own Sun. The spectrum from the light of the supposed planet indicates that it is too young and too small to be a small star, so they believe that it is indeed a planet.

However, they will still need to use more traditional techniques that measure the effect of the planet on its parent star, such as wobbling due to the mutual gravitational pulls or a tiny reduction of starlight as the planet passes in front of the star, to confirm that it is really a planet and not a small star that just happens to look like it's nearby. This could take a couple of years.

If you're interested in this kind of news and yet first learnt of it here, head over to the Bad Astronomer, who has an excellent writeup about the observation.