Big Promise in Little Telescope’s Discovery

Using a technique that could open a new phase of discovery, a tiny telescope has spotted a planet circling a faraway star, scientists said Tuesday.

The 4-inch-diameter telescope -- about the size a backyard astronomer might use -- tracked the periodic dimming of light from a star 500 light-years away. That dimming suggested the presence of a big planet regularly blocking out a small portion of light as it passed between the star and Earth. Later observations by the Keck I telescope in Hawaii, which has a diameter of 33 feet, confirmed the find.

More than 100 such exoplanets, or planets orbiting a star other than our sun, have been found in the last decade, but most have been discovered by observing stars that have a characteristic wobble, indicating a planet is nearby.

The telescope that found this planet is part of a network of modest instruments called the Trans-Atlantic Exoplanet Survey, known as TrES, which is designed to look for planets orbiting bright stars.

A statement from the Harvard-Smithsonian Center for Astrophysics said the find “demonstrates that we are at the cusp of a new age of planet discovery.”

The planet, called TrES-1, is a gas giant about the size of Jupiter, located in the constellation Lyra. TrES-1 orbits its star about once every three days at a distance of 4 million miles.