An international team of astronomers on the island of La Palma in the Canary Islands, Spain, has for the first time measured the transit of a super-Earth in front of a Sun-like star using a ground-based telescope.
Using a moderate-sized, but state-of-the-art instrument located at La Palma’s international observatory, the astronomers measured the dimming of the star’s light caused by the planet crossing in front of the star. The observations will be detailed in the Astrophysical Journal Letters.
Detecting the transit is important because it is the initial step in analyzing the planet’s atmosphere, according to a statement by the Harvard-Smithsonian Center for Astrophysics.
The exoplanet, called 55 Cancri e, orbits a star located only 40 light-years from Earth and is faintly visible to the naked eye. Scientists are able to determine that the diameter of the planet is about twice that of Earth by calculating the amount starlight is dimmed during the planet’s transit. The planet is about eight times as massive as Earth.
“Our observations show that we can detect the transits of small planets around Sun-like stars using ground-based telescopes,” said lead author Ernst de Mooij of Queen’s University Belfast in the U.K. in a statement.
Mooij says this is particularly important because future space missions such as TESS and PLATO are expected to find many small planets orbiting bright stars and astronomers want to be able to follow-up on these discoveries with Earth-based telescopes.
NASA’s upcoming mission TESS is scheduled for launch in 2017 while the European Space Agency’s PLATO is due to take off in 2024. Both missions will be looking for rocky Earth-like planets transiting nearby stars.
“Observations like these are paving the way as we strive towards searching for signs of life on alien planets from afar,” said co-author Prof. Ray Jayawardhana of Canada’s York University in a statement. “Remote-sensing across tens of light-years isn’t easy, but it can be done with the right technique and a bit of ingenuity.”