Triple signal of ‘alien megastructure’ star baffles astronomers


#NASA #Megastructure – Triple signal of ‘alien megastructure’ star baffles astronomers : The mystery of the so-called “alien megastructure” star just deepened. KIC 8462852, as it is more properly known, flickers so erratically that one astronomer has speculated that nothing other than a massive extraterrestrial construction project could explain its weird behaviour. A further look showed it has been fading for a century. Now, fresh analysis suggests the star has also dimmed more rapidly over the past four years – only adding to the enigma.

“It seems that every time someone looks at the star, it gets weirder and weirder,” says Benjamin Montet at the California Institute of Technology, who led the study.

This space oddity was first spotted by NASA’s Kepler space telescope, which continually monitored 100,000 stars from 2009 to 2013. Any dip observed in a star’s light is a sign that an exoplanet has passed in front of it. These dips, which occur regularly, block at most 1 per cent of the star’s light and have revealed thousands of exoplanets.

But KIC 8462852, also known as Tabby’s star after its discoverer Tabetha Boyajian of Yale University, was an outlier. Its light dipped by as much as 20 per cent and didn’t conform to any regular time intervals – so the signature couldn’t have been caused by a planet.

Astronomers came up with an array of potential explanations, from the mundane to the bizarre. The star made headlines when Jason Wright, an astronomer at Pennsylvania State University, announced that an advanced extraterrestrial civilization could be responsible for the signal.