New Research May Have , Solved Mystery Surrounding , 'Ghost' Stars.br Scientists say that they may be starting to unravel the br mystery surrounding "ghost" stars which align in beautiful br structures near the center of our Milky Way Galaxy.br 'The Independent' reports that br the unusual alignment of planetary br nebulae was first discovered ten years ago.br Since its discovery, the nature of the br "ghost" stars has remained a mystery.br Planetary nebulae are large clouds of gas br that are ejected from stars when br they come to their explosive end. .br Researchers studied a range of planetary nebulae near the center br of the Milky Way, some of which had assembled themselves br into beautiful shapes like butterflies or hourglasses.br According to the new study, scientists br believe the alignments happen when br these stellar ghosts have a companion star.br This finding pushes us closer br to understanding the cause br for this mysterious alignment, Albert Zijlstra, co-author and professor in astrophysics br at The University of Manchester, via 'The Independent'.br Planetary nebulae offer us a window into br the heart of our galaxy and this insight br deepens our understanding of br the dynamics and evolution of br the Milky Way’s bulge region, Albert Zijlstra, co-author and professor in astrophysics br at The University of Manchester, via 'The Independent'.br The significance in this research lies br in the fact that we now know that br the alignment is observed in this very br specific subset of planetary nebulae, Albert Zijlstra, co-author and professor in astrophysics br at The University of Manchester, via 'The Independent'.br The team's findings were published in br the 'Astrophysical Journal Letters.