A planet about a third the mass of Jupiter circles a sunlike star in about five days.
The discovery may not seem much different from the other 1,000 or so exoplanets identified to date. But the new planet, called YBP1194b, orbits a twin of the sun in the Messier 67 star cluster. The cluster, which is about 2,500 light-years from Earth in the constellation Cancer, has about 500 stars with roughly the same age and chemical composition as the sun.
The results are the first to identify a planet orbiting a solar twin in a star cluster and also confirm that planets are equally common in star clusters and around loner stars, astronomers report January 15 in Astronomy & Astrophysics.