Astronomers at NASA have discovered a unique six-star system located about 2,000 light-years from Earth. The system, TIC 168789840, has 3-pairs of stars whirling about each other.
The stars in TIC 168789840 are too far from Earth to be seen clearly through a telescope so scientists used a bit of astronomy-magic to spot them. The stars orbit on a plane that lines up perfectly with Earth. Due to the convenient alignment, every time one of the stars passes another, an eclipse is created which causes a ebb and flow of light when viewed from Earth. Scientists could then use years of observational data to look for cycles of dimming and lighting and then determine the dimming was caused by a pair of stars rotating around each other.
A system of 6-stars, a sextuple system, is not uncommon. But 6 stars consisting of three-pairs of stars is pretty unique. The pairs of stars in TIC 168789840 rotate around each other at different cycles. One pair rotates in a very tight, spinning circle while the other two have much wider orbits.
Scientists believe it would be difficult for planets to exist in the system. They would likely be swallowed up by one of the stars and ejected into space. A big question remains, however. Scientists still don’t understand how complex multiple star systems form.