Gaia will be able to measure the angles of inclination with far greater precision than ever before for stars up to 30,000 light years away.

Scientists will soon have precise distance measurements for the one billion stars that Gaia is mapping - but that's still only one percent of the stars in the Milky Way.

The researchers found that the difference of the distances of the twin stars is directly related to the difference in their apparent brightness in the sky, meaning that distances can be accurately measured without having to rely on models.

"The further away a star is, the fainter it appears in the sky, and so if two stars have identical spectra, we can use the difference in brightness to calculate the distance," Dr Pfeil noted.

The next step is to compile a "catalogue" of stars for which accurate distances are available and then search for twins among other stellar catalogues for which no distances are available.

The details of the new technique have been published in the journal Monthly Notices of the Royal Astronomical Society.