Spanish and UCL (University College London) scientists have discovered a possible terrestrial-type planet orbiting a star in the constellation of Leo. The new planet, which lies at a distance of 30 light years from the Earth, has a mass five times that of our planet but is the smallest found to date. One full day on the new planet would be equivalent to three weeks on Earth.
The team of astronomers from the Spanish Research Council (CSIC) working with Dr Jean-Philippe Beaulieu, a visiting astrophysicist at UCL, made the discovery from model predictions of a new exoplanet (meaning planet outside our solar system) orbiting a star in the constellation of Leo. Simulations show that the exoplanet, dubbed GJ 436c, orbits its host star (GJ 436) in only 5.2 Earth days, and is thought to complete a revolution in 4.2 Earth days, compared to the Earth’s revolution of 24 hours and full orbit of 365 days. On Earth, a full day (sunset to sunset) coincides quite closely with the rotation period. On the new planet these two periods do not coincide, since the orbital translation period and the rotation period are very similar. For this reason, a full day on the new planet would take four planetary years, or roughly 22 Earth days.