Researchers found a rare planet orbiting a "solar twin" almost identical to our Sun.
A research team recently discovered three planets in the star cluster Messier 67; very few planets have been found in star clusters (the birthplace of many stars) in the past, a European Southern Observatory news release reported.
Since so few planets have been found in the past, researchers believe there may be something preventing planet formation in the regions.
"In the Messier 67 star cluster the stars are all about the same age and composition as the Sun. This makes it a perfect laboratory to study how many planets form in such a crowded environment, and whether they form mostly around more massive or less massive stars," Anna Brucalassi, of the Max Planck Institute for Extraterrestrial Physics, said.
Messier 67 is about 2,500 light-years away from Earth and resides in the Cancer constellation (which contains only 500 stars).
To make their findings the researchers used the HARPS planet-finding instrument along with comparisons from other parts of the world. The team looked at 88 stars located in Messier 67 over the course of six years, especially focusing on "tiny telltale motions of the stars towards and away from Earth that reveal the presence of orbiting planets," the news release reported.
The research team was able to locate three planets in the star cluster; two of the newly-discovered planets are believed to orbit Sun-like stars while the other is hosted by an older red giant.
The first two planets are believed to be about a third of the mass of Jupiter and orbit their host stars in only a few days, most likely making them too hot to support life. The third planet orbits its star in 122 days in is more massive than Jupiter, the largest planet in our solar system.
The star supporting the first planet discovered may be the most Sun-like researchers have ever seen; it is essentially identical to our own host star. The discovery marks the "first solar twin in a cluster that has been found to have a planet," the news release reported.
All three newly-discovered planets orbit outside of the "habitable zone," and are too hot to contain water.
"These new results show that planets in open star clusters are about as common as they are around isolated stars -- but they are not easy to detect," Luca Pasquini (ESO, Garching, Germany), co-author of the new paper, said. "The new results are in contrast to earlier work that failed to find cluster planets, but agrees with some other more recent observations. We are continuing to observe this cluster to find how stars with and without planets differ in mass and chemical makeup."
