Unique quadruple-star system spotted by astronomers

Dense core

“All stars form in the densest gas region of the molecular cloud known as "dense core". Previous observation has shown that more "star babies" are in a stellar system, the smaller the proportion they take up in the whole. For higher-order stellar systems with over two star-members, how they are formed in dense cores remains ambiguous due to insufficient observations,” noted the press statement.

To understand the complex science behind these intricate formations, the ALMASOP team conducted a high-resolution analysis of 72 young and cold cores in the Orion GMC, studying the thermal emission of dust at a wavelength of 1.3 mm. 

“They discovered a quadruple protostellar system in G206.93-16.61E2, a dense cold core located at 1,500 light-years from Earth within the Orion B GMC. The system consists of four members: two protostars, and two prestellar gas condensations that may also form low-mass stars in future,” revealed the press release.

The new celestial bodies were further found to have a separation of only one thousand astronomical units between them likely supported by several ribbon-like elongated structures in dust emission that connect the four objects together.

"The exceptional compactness and close-proximity of this system is a fascinating discovery. The analysis suggests that this system is very likely to form a gravitationally bound quadruple star system in the future," said Ph.D. Luo Qiuyi at SHAO and the first author of the study. 

Continuum ribbons

The researchers took a particular interest in the continuum ribbons, comparing them to those found in another quadruple system. This process revealed that the extending continuum ribbons can serve as conveying funnels, bringing in gas materials from the outer envelope/core all the way to the protostars.

"The simulation supports that these ribbons can serve as large-scale accretion streamers. Thus, the two gas condensations in the system have the potential to form a star relying on the feeding of these continuum ribbons," explained Tie. "The accretion streamers could also fragment, and further form new stars."

However, the researchers' work is not done as some elements of the newly-discovered celestial bodies remain a mystery.

"We do not have an explanation of how the gas outflows propagate as they might be entangled with gas accretion processes of system members," commented Qiuyi.