Astronomers have been watching the “megastructure” star – officially known as KIC 8462852 – as it is known for bizarrely dimming.
It is known as the alien megastructure due to theories the dimming might be down to a large spaceship or object orbiting the star.
While scientists remain unconvinced by this idea, the object – also known as Tabby’s Star – still has them baffled.
KIC 8462852 is around 1,280 light years from Earth and is currently being monitored by the Kepler space telescope.
Astronomers have this week recorded the star’s largest dimming event to date.
Tabby’s Star starting dimming on March 16, before lighting up again, and then resumed dimming on March 26.
Scientists said this is the “deepest dip” since they started monitoring the so-called alien megastructure – getting about 10% darker than usual.
The star has previously been dubbed the “most mysterious” in the universe.
Mystery still surrounded why the star is blinking, whether it is an alien megastructure, planets orbiting the star, or a cloud of dust.
Astronomer Tabetha Boyajian, for whom the star is named, revealed the latest dimming on Twitter.
The assistant professor of Astrophysics at Louisiana State University posted it was the “deepest dip detected”.
She remains uncertain as to what is causing the dimming, but space watchers around the world are keeping tabs on Tabby’s Star.
NASA’s Kepler space telescope focuses on watching dimming stars since it is a way to uncover new planets.
Stars dim when planets orbiting the stars pass in front of them, causing regular dimming events.
The “alien megastructure” is unusual as the star is totally unpredictable in its darkening – and sometimes getting brighter.
This is what has led to theories about alien space ships potentially visiting the star as a fuel source.
Previously, Professor Boyajian said: 'Dust is most likely the reason why the star’s light appears to dim and brighten.
'The new data shows that different colours of light are being blocked at different intensities.
'Therefore, whatever is passing between us and the star is not opaque, as would be expected from a planet or alien megastructure.”