First ground-based telescope detection of super-earth transit may help sense future small exoplanets

Astronomers were recently able to detect super-earth transit through a ground-based telescope for the first time ever, which have paved way for remote sensing of future small exoplanets.

Astronomers have measured the passing of a super-Earth in front of a bright, nearby Sun-like star using a ground-based telescope for the first time. The transit of the exoplanet 55 Cancri e is the shallowest detected from the ground yet.

Since detecting a transit was the first step in analyzing a planet's atmosphere, this success bodes well for characterizing the many small planets that upcoming space missions are expected to discover in the next few years.

The international research team used the 2.5-meter Nordic Optical Telescope on the island of La Palma, Spain, a moderate-sized facility by today's standards but equipped with state-of-the-art instruments, to make the detection.

The host star, 55 Cancri, is located just 40 light-years away from Earth and is visible to the naked eye. During its transit, the planet crosses 55 Cancri and blocks a tiny fraction of the starlight, dimming the star by 1/2000th (or 0.05 percent) for almost two hours. This shows that the planet is about twice the size of Earth, or 16,000 miles in diameter.