LONDON (TIP): Water has been detected in the atmosphere of a planet outside our solar system. An international team of astronomers detected water in the atmosphere of Tau Bootis b which is as massive as Jupiter orbiting the star Tau Bootis. Chad Bender, a research associate in the Penn State Department of Astronomy in the US and used a new technique that could help researchers to learn how many planets with water, like earth, exist throughout the universe.

Chad said “Planets like Tau Bootes b which are as massive as Jupiter but much hotter do not exist in our solar system. Our detection of water in the atmosphere of tau Bootis b is important because it helps us understand how these exotic hot-Jupiter planets form and evolve. It also demonstrates the effectiveness of our new technique, which detects the infrared radiation in the atmospheres of these planets.”

The co-authors of the paper are at institutions including CalTech, Penn State University, the Naval Research Laboratory, the University of Arizona, and the Harvard-Smithsonian Center for Astrophysics. Bender is leading a larger project to characterize the atmospheres of many hot-Jupiter extra-solar planets. Scientists had previously detected water vapor on a handful of other planets using a technique that works only if a planet has an orbit that passes it in front of its star when viewed from Earth.

Scientists also were able to use another imaging technique that works only if the planet is sufficiently far away from its host star. But significant portions of the population of extra-solar planets do not fit either of these criteria and there had not been a way to discover information about the atmospheres of these planets. “We now are applying our effective new infrared technique to several other non-transiting planets orbiting stars near the Sun,” Bender said.

“These planets are much closer to us than the nearest transiting planets, but largely have been ignored by astronomers because directly measuring their atmospheres with previously existing techniques was difficult or impossible,” he added. With the new detection technique and morepowerful telescopes in the future like the James Webb Space Telescope and the Thirty Meter Telescope, the astronomers expect to be able to examine the atmospheres of planets that are much cooler and more distant from their host stars where liquid water is even more likely to exist.