From College Park, Md., at the Annual October Astronomy Meeting
Among the more than 100 extrasolar planets discovered since 1995, nearly all have been detected by measuring the tiny wobble they induce in the motion of their parent stars. But a few have been found by recording the tiny dip in starlight that occurs each time the putative planet passes in front of the star it orbits. This so-called transit method, which requires a rare alignment among the star, the planet, and Earth, yields both the radius and mass of a planet. The wobble technique can reveal only a lower limit for the mass.
The astronomers who last January reported finding the first planet using the transit method (SN: 1/18/03, p. 38: Available to subscribers at Distant and Strange: Orb isn't just another extrasolar planet) have now refined their estimate of the planet's mass. Rather than weighing nearly as much Jupiter, the newfound planet, designated OGLE-TR-56b, is abo