The degree of dimming during the planetary transits — those times that a planet crosses the path of something else — usually allows Kepler astronomers to measure the size of a planet relative to the stars. As a result, (uncertainties) in the properties of stars propagate into uncertainties of as much as 25 percent in the mass of a planet — enough to blur the line between a rocky planet and a gaseous one.
But in the Kepler 16 system, by (comparing) slight variations in the timing of the transits with calculations of the positions of the stars and the gravitational nudges the bodies give one another, Dr. Doyle’s team could (deduce) the absolute masses and sizes of the stars and planets in the system. That is a tool, they say, that is becoming increasingly valuable for (determining) the masses of small planets in multiple-planet systems.
As a result, said Dr. Doyle, “it’s a laboratory for all sorts of physics and stellar evolution.”
The Tatooine laboratory will be available to a wide audience for at least a while longer. Dr. Doyle noted that amateur (astronomers) in northern Asia, equipped with as little as an eight-inch telescope and an off-the-shelf C.C.D. detector an electronic device that cameras use to (capture) images, would be able to record the passage of the Tatooine planet across the brighter star in its system on June 28 next year.
But enjoy it while you can. Because of (variations) in the planet’s orbital plane, as seen from Earth, the planet will stop crossing one of the stars as soon as 2014 and cease transiting the other, (brighter) one in 2018. It will be around 2042 before the show starts up again for Earthlings.
