Overcoming interference from a very active young sun-like star, a group of astronomers were able to find what they determined is the youngest exoplanet yet discovered. BD+20 1790b is 35 million years old (Earth is about 100 times older at 4.5 billion years) and is located about 83 light years away from our planet. Previously, the youngest known exoplanet was about 100 million years old. Studying this planet will help our understanding of planetary evolution.
While this new-found planet is young, it is a whopper, at six times the mass of Jupiter. It orbits a young active star at a distance closer than Mercury orbits the Sun.
Most planet-search surveys tend to target much older stars, with ages in excess of a billion years. Young stars usually have intense magnetic fields that generate solar flares and sunspots, which can mimic the presence of a planetary companion and so can make extremely difficult to disentangle the signals of planets and activity.
BD+201790 is a very active star, and astronomers announced last year that it could possibly have a companion. An international collaboration of astronomers, led by Dr. Maria Cruz Gálvez-Ortiz and Dr. John Barnes were able to “weed out” the data to determine the planet was actually there.
“The planet was detected by searching for very small variations in the velocity of the host star, caused by the gravitational tug of the planet as it orbits – the so-called “Doppler wobble technique,” said Gálvez-Ortiz. “Overcoming the interference caused by the activity was a major challenge for the team, but with enough data from an array of large telescopes the planet’s signature was revealed.”
The team has been observing the star for the last five years at different telescopes, including the Observatorio de Calar Alto (Almería, Spain) and the Observatorio del Roque de los Muchachos (La Palma, Spain).
Source: Alpha Galileo