The mysteries of one of the most fascinating nearby planetary systems now have been solved, claim researchers.
The study, which presents the first viable model for the planetary system orbiting one the first stars discovered to have planets-the star named 55 Cancri-was led by Penn State University graduate student Benjamin Nelson in collaboration with faculty at the Center for Exoplanets and Habitable Worlds at Penn State and five astronomers at other institutions in the United States and Germany.
Numerous studies since 2002 had failed to determine a plausible model for the masses and orbits of two giant planets located closer to 55 Cancri than Mercury is to our Sun.
By combining multiple types of observations, the Penn State astronomers determined that one of the planets in the system (55 Cnc e) has eight times the mass of Earth, twice the distance of Earth's radius, and the same density as that of Earth. This planet is far too hot to have liquid water because its surface temperature is estimated to be 3,800 degrees Fahrenheit, so it is not likely to host life.
It was only in 2011, 8 years after the discovery of this inner-most planet (55 Cnc e) that astronomers recognized it orbited its host star in less than 18 hours, rather than nearly 3 days, as originally thought. Soon after, astronomers detected the shadow of the planet passing over the Earth, allowing astronomers to measure the size of the planet relative to the size of the star.
The 55 Cancri planetary system is just 39 light years away in the constellation Cancer.
The scientific paper is set to be published online in the journal Monthly Notices of the Royal Astronomical Society.