At a distance of 4.2 light-years from Earth, Proxima Centauri is just 0.2 light-years from the more-distant binary star Alpha Centauri A+B. These three stars are considered part of the triple-star system that is closest to Earth, although right now Proxima Centauri is the closest of the three stars. Astronomers would like to know if Proxima has any planets around it. Because Proxima is the closest star, there is a chance in the next two years that as the star passes in front of more distant stars, a tiny perturbation by Proxima, or perhaps one of its planets (if it has any), will distort the positions of the background stars as we see them. This effect is called microlensing and could provide the mass of Proxima as well as information about planets if they are there. HubbleSite news release Space.com on the search for Proxima Centauri's planets