Alpha Centauri, the closest star system to the Earth, may be home to some small, Earth-like planets which have been overlooked so far, astronomers say. This star system is located in the constellation of Centaurus at a distance of 4.3 light-years from Earth. It has three stars — Centauri A, Centauri B, and Proxima Centauri. “The universe has told us the most common types of planets are small planets, and our study shows these are exactly the ones that are most likely to be orbiting Alpha Centauri A and B,” said one of the lead researchers Debra Fischer, Professor at Yale University in the US. The study, published in the Astronomical Journal, ruled out the existence of a number of larger planets in the system that had popped up in previous models. “Because Alpha Centauri is so close, it is our first stop outside our solar system,” Fischer said. “There’s almost certain to be small, rocky planets around Alpha Centauri A and B,” Fischer said.
For Proxima Centauri, there might be orbiting planets that are less than one-half of Earth’s mass, the study said. The findings are based on data coming in from a new wave of more advanced spectrographic instruments at observatories located in Chile. “This is a very green study in that it recycles existing data to draw new conclusions,” said Lily Zhao, graduate student at Yale University. “By using the data in a different way, we are able to rule out large planets that could endanger small, habitable worlds and narrow down the search area for future investigations,” Zhao added.
This new information will help astronomers prioritize their efforts to detect additional planets in the system, the researchers said.