Proxima Centauri Star Is More Like Sun Than Thought: What Does It Imply For Proxima B?

In August this year, astronomers declared the discovery of a "second Earth" orbiting the Proxima Centauri star, located four light years away. The Earth sized exoplanet called Proxima b, made, and is in fact still making, a lot of noise among the community of scientists and space watchers who believe it to have a temperature suitable for the existence of liquid water, and hence be suitable for hosting alien life. Now, researchers from Harvard have found that not only are there chances of Proxima b being similar to Earth, but its star the Proxima Centauri is also quite like our star, the Sun.  

The researching team has reportedly found that the Proxima Centauri - a cool, small, red dwarf star that has only one-tenth the mass of the Sun and one-thousandth as luminous - has a regular cycle of starspots, also known as sunspots. Starspots are basically like blotches on the surface of the star that occur where the temperature is lower than the surrounding area. Starspots are driven by magnetic fields which can obstruct the surface plasma and create spots. The number and distribution of such spots are affected by the frequency of changes in the magnetic field.

The Sun has an 11 year activity cycle wherein it is practically spot free during the solar minimum. On an average more than 100 starspots cover an area of less than one percent surface area during solar maximum. According to the recent research, the Proxima Centauri undergoes a similar cycle that lasts for seven years from minimum to maximum, and at least one-fifth of its surface is covered in spots at any given time and those starspots are relatively larger than sunspots.

The study does not address if the discovery about Proxima Centauri has a bearing on the habitability of Proxima b. However, "if intelligent aliens were living on Proxima b, they would have a very dramatic view," said lead author Brad Wargelin of the Harvard-Smithsonian Centre for Astrophysics (CfA). It has been suggested by scientists that a stellar wind or flares could strip the atmosphere off the planet making it like our moon, in the habitable zone.