Free Astronomy Magazine July-August 2020

8 JULY-AUGUST 2020 ima Centauri oscillation, this minimum mass for the planet turned out to be approximately 30% greater than that of the Earth. If the orbital plane of the Proxima Centauri system deviates even more from our own, it be- comes necessary to con- sider proportionally more relevant masses to explain the forward-backward os- cillation of Proxima Cen- tauri. Theoretical considerations of the size of the planet led its discoverers to esti- mate its diameter to be in the range of 0.9-1.4 Earth diameters, a size compar- atively similar to Earth’s. A part of the surprise of the discovery of Proxima b was due precisely to its size, while the rest of the surprise was attributable to the fact that it orbits within the habitable zone of Proxima Centauri and receives a total amount of en- ergy comparable to what the Earth receives from the Sun. The observed similarities end there, and we now wait for the direct ob- servation and study of that elusive planet H ere’s what Proxima b could look like, the only con- firmed planet in orbit around Proxima Centauri. [Ricardo Ramirez and James Jenk- ins, University of Chile] Left, Guillem Anglada-Escudé, the team leader who discovered Proxima b. [Jay Brooks] that is, for now, only perceivable through the very small oscillation of the spectral lines of the red dwarf. This discovery was enough to push many other researchers to further intensify their observations of the Proxima Centauri system. Among those re- searchers were Mario Damasso (National In- stitute for Astro- physics − INAF, Pino Torinese Ob- servatory, Italy) and Fabio Del Sordo (University of Crete). On the occasion of the Break- through Discuss in April 2019 (a part of the Break- through Initia- tives program), these two as- tronomers an- nounced that they had discov- ered evidence of