Kepler telescope glimpses freefloating planets

To find signals in the Kepler data, new data reduction techniques were needed.Iain writes: 'These signals can be extremely difficult to locate.' We pointed an old, blurred-vision telescope at the densely populated sky. One out of every million stars of our Galaxy is visible affected by microlensing, though only a small percentage of these can be attributed to planets.Kepler was not intended to search for planets with microlensing or to study dense star fields in the inner Galaxy. This causes a brief burst of brightness that can last for hours or days. It describes how light from a background star can temporarily be magnified by other stars in its foreground. These planets could have formed originally around a star, before being ejected from the gravitational pull of heavier planets in this system.Microlensing was predicted by Albert Einstein 85 year ago, as a result of his General Theory of Relativity. This suggests that they may be free-floating, or even planetary events. The four shortest events, however, are new discoveries consistent with similar-sized planets to Earth.These new events don't show the accompanying longer signal expected from a star. Many of these signals were previously observed in ground data. Kepler observed a dense field of millions stars close to the center of the Galaxy for two months in order to detect rare gravitational microlensing phenomena.The team discovered 27 candidate microlensing signals with short durations that varied in time between one hour and 10 days. The data used for the study were obtained during NASA's K2 mission phase of its Kepler Space Telescope. Four new discoveries, which are consistent with Earth-sized planets, were published in Monthly Notices of the Royal Astronomical Society.Iain McDonald, now at the Open University in the UK, was the study's leader. Credit: Pixabay/CC0 public domainTantalizing evidence has been found for a mysterious group of 'free-floating', or unbound, planets.

Kepler telescope glimpses freefloating planets