Multi-planet System found through crowdsourcing

Saturday, 13 Jan, 2018

The planets also appear to orbit their star in concentric circles, forming a tightly packed planetary system, unlike our own elliptical, far-flung solar system. The size of each planet's orbit appears to be a ratio of the other orbits, suggesting that all five planets originally formed together in a smooth, rotating disc, and over eons migrated closer in towards their star.

The announcement was made Thursday at the ongoing 231st meeting of the American Astronomical Society in Washington, D.C., by researchers from Massachusetts Institute of Technology (MIT) and California Institute of Technology (Caltech). This discovery of five new exoplanets by citizen scientists has been confirmed by the scientists of Massachusetts Institute of Technology (MIT) in the United States as well as the CALTECH in Pasadena. However, the following year, scientists reprogrammed the spacecraft's thrusters and remaining wheels, enabling the telescope to point at certain parts of the sky for limited periods.

The K2 data was mostly light curves, showing the intensity of light from individual stars.

As citizens contributing to the Exoplanet Explorers shared, K2 had a whole new field of stars that might host planets, contained in a dataset called C12 that no astronomer had yet thought to look through.

Another batch of 2017 Kepler data was recently uploaded to Exoplanet Explorers for citizen scientists to peer through. In contrast, K2 has been driven mainly by decentralized, community-led efforts. In the time that it takes for the innermost planet to make eight orbits, the second, third and fourth planets revolve five, three and two times around the star, respectively.

The Exoplanet Explorers citizen scientist project, the brainchild UC Santa Cruz astronomer Ian Crossfield and Caltech staff scientist Jessie Christiansen, began its search for new planets on crowdsourcing research platform Zooniverse. They designed a training programme to first teach users what to look for in determining whether a signal is a planetary transit.

"People anywhere can log on and learn what real signals from exoplanets look like, and then look through actual data collected from the Kepler telescope to vote on whether or not to classify a given signal as a transit, or just noise", says Christiansen. For the signals to get confirmed for further analysis by researchers, at least ten users should look at a potential signal and then ninety percent of users should have to vote "yes" for that signal. According to him, the project was exciting as they got the public excited about science and it really leveraged the power of the human cloud. But it was a feature on the ABC Australia television series Stargazing Live that ultimately yielded the most new data from citizens. And that is how the five exoplanets of K2-138 were found. Over 48 hours, the users made almost 2 million classifications from the available light curves. They statistically validated the set of planet signals as being "extremely likely", according to Christiansen, to be signals from true planets. The five exoplanets are orbiting a far-off sun-like star called K2-138 which is situated nearly 620 light years away from Earth in the constellation Aquarius. The instrument identifies potential planets around other stars by looking for dips in the brightness of the stars that occur when planets cross in front of, or transit, them.

This is the first multi-planet system discovered entirely through crowdsourcing.

This artist concept shows K2-138, the first multi-planet system discovered by citizen scientists. "And the human eye in many cases is very effective in separating the planetary wheat from the nonplanetary chaff", Crossfield said in a statement Thursday.

In particular, he envisions that the public will one day be able to analyze data taken by TESS, the Transiting Exoplanet Survey Satellite, which is set to launch later this year.