26 Mayo 2017 16:09
Its light keeps dimming at random
The strangest star is behaving oddly again. Tabby's Star, named after its discoverer, Tabetha Boyajian, is fluctuating at random.
Another possible explanation is that the star is surrounded by a dust cloud, as is often the case with young stars which are still accumulating mass. However, Tabby's Star is mature, so this seems unlikely.
In late 2015, one astronomer, Jason Wright from Penn State, posited an alternative theory to explain the strange phenomenon – a theory that instantly shot the star to fame. He suggested that megastructures created by an alien civilisation were orbiting the star in order to harness its energy – like a Dyson sphere. 'Aliens should always be the very last hypothesis you consider,' Wright told The Atlantic at the time, 'but this looked like something you would expect an alien civilization to build.'
Tabby's Star has been dimming dramatically over the past four years. No other star behaves like this.
The alien megastructure theory has been largely rejected because, as astrophysicist Bradley Schaefer has pointed out, such a structure would radiate heat that has not been reflected in any of the observations. However, the fact is that no other satisfactory answers have been found.
Last Thursday, astronomer Matt Muterspaugh noticed that the star – whose official name is KIC 8462852 – was acting up again. Telescope data taken from the night before showed that the brightness of the star had dipped significantly. He contacted other astronomers who had also been observing the same star, to let them know what he had seen and to keep an eye on it for any more changes. Now, all the telescopes of the world are trained on Tabby's Star to try and figure out what is going on.