Scientists Discover Unusual Star System Orbiting Around Sun, Astronomers Explain How the Discovery Came to Be

Astronomers have discovered a triple star system that has never been observed before. It's possible that the stellar triplets once had a fourth sibling before one of the others devoured it since the odd trio of stars is considerably more massive and tightly packed together than a conventional triple system.

Scientists using NASA's transiting exoplanet observatory (TESS) found the tertiary (triple star system) known as TIC 470710327, orbiting around the Earth. The trio is organized hierarchically, with a third star orbiting the central pair of binary stars as they circle one another in the system's center, Live Science reported.

TESS data from earlier this year were used to identify TIC 470710327, followed by the HERMES spectrograph on the 1.2-m Mercator Telescope at the Roque de Los Muchachos Observatory on the island of La Palma.

Astronomers Find One-Of-A-Kind Massive, Compact System of Three Stars

Due to its size and form, TIC 470710327 differs from all other known tertiary systems. The trio is significantly more compact since they all have larger gravitational pulls than usual. The stars are substantially more massive than the ordinary stars seen in a tertiary system.

"As far as we know, it is the first of its kind ever detected," astronomer and postdoc Alejandro Vigna-Gomez said in a statement by the Niels Bohr Institute. "We know of many tertiary star systems (three star systems), but they are typically significantly less massive. The massive stars in this triple are very close together - it is a compact system."

The tertiary star has an inner orbit that is round in form and has a mass roughly 16 times that of our sun, Interesting Engineering pointed out. The tertiary star makes about six rotations around twice a year.

Triple Star Characteristics: How It Came To Be

Triple star systems are uncommon in deep space; according to NASA, just 10 percent of all star systems are now in the universe. The system is larger than any earlier finding in this sector, although the first of its kind was found in September 2021.

The scientists programmed the possibilities and carried out more than 100,000 computer iterations to determine the most likely formation scenario.

Their findings supported the idea that two binary systems would initially develop, with one of them eventually merging to produce a single star.

SciNews, citing the researchers, mentioned that such stellar mergers typically produce highly magnetic, slowly spinning blue stars on the main sequence.

High-inclination triple- and quadruple-star systems are predicted to undergo stellar mergers and become binary- and triple-star systems under this formation scenario.

The next challenging step for the scientists was to try to picture the conditions that gave rise to the star system. According to Interesting Engineering, there were three possibilities:

• A near pair would not have developed if, for example, the larger star formed first since it is likely to have expelled material that would have interfered with the process.
• Another hypothesis is that the third star and the binary evolved independently of one another before colliding and becoming locked in place by gravity.
• A third scenario in which two binaries developed, with one merging to produce a single, larger star.

The team's research titled "Mergers prompted by dynamics in compact, multiple-star systems: a stellar-reduction case for the massive triple TIC 470710327," was published in the Monthly Notices of the Royal Astronomical Society: Letters.

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