In a groundbreaking revelation that challenges existing theories on stellar formation, international researchers have made significant strides in understanding the birth of binary and multiple-star systems. Utilizing the Atacama Large Millimeter/submillimeter Array (ALMA) in Northern Chile, the team has studied IRAS 04239+2436, a triple system of protostars located approximately 460 light-years away from our planet. This unique system, surrounded by intriguing gas structures known as streamers, offers a critical glimpse into the enigmatic process of multiple star system formation.
Astrophysicist Tomoaki Matsumoto of Hosei University, a collaborator on the study, remarked that this is the first time the origins of protostars and streamers have been simultaneously and comprehensively explained. The synergy between ALMA’s observations and advanced simulations has unlocked some of the mysteries surrounding star formation. Stars are born when gravity pulls in gas, forming a disk and a growing protostar at its center in a process known as accretion. This process also forms streams of infalling gas, or streamers, which act like conveyor belts, transporting material inward. Until now, the formation of these streamers remained unclear.
Solving Stellar Mysteries: New Insights on Star Formation
Astrophysicists have taken a significant step forward in understanding the birth of binary and multiple-star systems, thanks to high-resolution observations by the Atacama Large Millimeter/submillimeter Array (ALMA) in Northern Chile. The recent study reveals crucial moments in the formation process of a triple star system, shedding light on some long-standing mysteries of star formation.
Unraveling the Birth of Stars
The focus of the study was IRAS 04239+2436, a triple system of protostars about 460 light-years from Earth, adorned with mesmerizing structures of gas known as streamers. Until now, the origin of such protostars and their streamers was shrouded in mystery. "This is the first time that the origin of protostars and the streamers have been simultaneously and comprehensively clarified," expressed astrophysicist Tomoaki Matsumoto of Hosei University, a collaborator on the study.
Stars are born when gravity pulls in gas, causing it to coalesce in a process known as accretion, forming a disk and a budding protostar at its center. This process also forms streamers of infalling gas that act as cosmic conveyor belts, shuttling material inward. However, the formation of these streamers remained an enigma until now.
A Cosmic Dance of Gas and Stars
Using the ALMA radio telescope, the researchers observed radio waves from sulfur monoxide molecules, which illuminate when gas in the system undergoes violent shock. The team discovered three spiral arms around the system’s three protostars and traced their outlines. By analyzing the motion of the gas, they confirmed these arms were streamers, supplying the young stars with the material required for growth.
Lead author and astrophysicist Jeong-Eun Lee from Seoul National University described the structures as “dancing together, spinning around the central protostellar system". These arms, extending up to 400 astronomical units, feed the triplet stars like a cosmic river flowing towards them.
Shaping the Streamers
To decipher how these spiral streamers formed, the team resorted to simulations on supercomputers ATERUI and ATERUI II, programmed by Matsumoto. The simulations revealed that the gas moving around the triplet stars generated shock waves, taking the shape of spiral arms. “The velocity of the gas derived from the simulations and the observations matches well, indicating that the numerical simulation can indeed explain the origin of the streamers,” stated Matsumoto.
A Hybrid Theory of Star Formation
The findings offer a fresh perspective on the process of multiple-star formation. The new hybrid scenario combines aspects of existing theories: seeds of protostars form as fragments of the disk, while the surrounding turbulent gas cloud shapes the spiral arms and causes them to extend widely.
Interestingly, the study also implies that planet formation could be challenging in multiple-star systems. Planets are born out of calm environments, from the disks of gas and dust surrounding protostars. However, the turbulent nature of multi-star systems, particularly compact ones like IRAS 04239+2436, leads to protostars stripping each other’s disks, making them less likely to be fertile grounds for planet formation.
The study offers a significant leap forward in understanding the complex process of star formation. The new hybrid theory might help to reconcile different viewpoints and further our understanding of the universe’s cosmic ballet. However, the finding that multi-star systems may not be conducive to planet formation also brings a new dimension to our understanding of where life as we know it may exist in the universe.