The planet is named HD 209458b, informally known as Osiris. It was first discovered in 1999. It is located in the constellation Pegasus, about 150 light-years from the Earth. One-hundred-fifty light-years is equal to approximately 1,419,000,000,000,000 kilometers (881,800,000,000,000 miles); that is, about 1,419 trillion kilometers (881.8 trillion miles). It is a 7th magnitude star, which is visible from the Earth with the use of binoculars.
U.S. astronomer Travis Barman, of the Lowell Observatory (Flagstaff, Arizona) made the announcement on Tuesday, April 10, 2007. His research results was made possible by analysis performed on the Hubble Space Telescope, measurements by Heather Knutson, from Harvard University (Cambridge, Massachusetts), theoretical models produced by Barman, and funds provided by NASA. The exciting result will be published in a future issue of the Astrophysical Journal.
Barman states that the finding of water on this exoplanet, or exosolar planet, (a planet outside of the solar system) is promising for finding other planets containing water.
Planet HD 209458b is also famous for being the first exoplanet to be found with an atmosphere and the first transiting exoplanet detected by astronomers here on the Earth. A transiting planet is one that orbits directly in front of a star so that it obscures a small part of that star’s disc for an observer on the Earth. In case of HD 209458b, it transits (crosses) in front of its star (HD 209458) every 3.5 days.
Life elsewhere in the solar system has yet to be discovered. However, astronomers are gathering bits and pieces of information, such as this exciting information from HD 209458b, to hopefully someday report news of the existence of extraterrestrial life.
Additional information about Planet HD 209458b is found at SPACE.com’s Web page: https://www.space.com/scienceastronomy/070410_water_exoplanet.html.
The home Web page for the Lowell Observatory is: https://www.lowell.edu/.