Astronomers have detected a triple star system that is unlike any that has been seen before.

The unusual trio of stars is more massive and closely squeezed together than a typical triple system. Because the stellar triplets used to have a fourth sibling before one of the others gobbled it up.

The triple, or tertiary, star system is known as TIC 470710327 and was detected by researchers using data from NASA's Transiting Exoplanet Survey Satellite (TESS) observatory that’s orbiting Earth.

The trio has a hierarchical structure, meaning a pair of binary stars circle one another at the center of the system.

10% of star systems in the universe could be tertiary, according to NASA. In September 2021, astronomers detected a single exoplanet orbiting a tertiary system for the first time.

TIC 470710327 stands apart from all the other known tertiary systems, because of its size and shape. the trio is much more compact, because they all exert a stronger gravitational pull than normal.

The new system was originally found by a citizen scientist, who was combing through the TESS database in search for abnormalities.

There are three potential explanations for how TIC 470710327 was created. The first possibility is that the large outer star formed first, and the smaller stars formed later.

The system was originally made up of two binary pairs, the one at the center of the system we see today and another pair orbiting where the more massive outer star currently sits.

The researchers want to continue searching for similarly massive and compact tertiary systems.