Scientists using the 2.5 meter Nordic Optical Telescope on the island of La Palma, Spain detected a super-Earth transit. It was the first time a ground-based telescope has successfully observed exoplanet 55 Cancri e transiting – when the planet moves in front of its host star.
It’s the second time a ground-based telescope has spotted a transiting super-earth. The first one was GJ1214b.
The international research team spotted the exoplanet moving in front of its host star, 55 Cancri. This star is located about 40 light-years away from us and is visible with the naked eye. The exoplanet managed to dim the star by just 0.05%.
“Our observations show that we can detect the transits of small planets around Sun-like stars using ground-based telescopes,” says Dr. Ernst de Mooij, the study’s lead author.
“This is especially important because upcoming space missions such as TESS and PLATO should find many small planets around bright stars.”
Measuring these minuscule changes from the ground is difficult due to the earth’s atmosphere.
“It’s remarkable what we can do by pushing the limits of existing telescopes and instruments, despite the complications posed by the Earth’s own turbulent atmosphere,” says Professor Ray Jayawardhana, the study’s co-author.
“Observations like these are paving the way as we strive towards searching for signs of life on alien planets from afar. Remote sensing across tens of light-years isn’t easy, but it can be done with the right technique and a bit of ingenuity.”
Here’s the telescope used to detect the exoplanet transit. It’s described as “a moderate-sized facility by today’s standard.”
The search for life won’t be happening on planet 55 Cancri e. It’s the closest of five planets in the star system with temperatures reaching more than 1700 Celsius on the dayside. That’s hot enough to melt metal. But, the detection of the planet means scientists won’t have to always rely on space telescopes for observations.
Space telescopes can make the initial discovery while ground-based telescopes can conduct follow-up research.
Ground-based telescopes could help support upcoming missions including NASA’s TESS (launching in 2017) and ESA’s PLATO (launching 2024). These missions will search for transiting planets around bright stars.
“We expect these surveys to find so many nearby, terrestrial worlds that space telescopes simply won’t be able to follow-up on all of them. Future ground-based instrumentation will be key, and this study shows it can be done,” says Lopez-Morales.
Image credits NASA/JPL (top image), Michael Hanselmann (telescope image)