A Massive Stream of Gas Tilts the Protoplanetary Disk of Triple-Star System GW Orionis

• A massive gas streamer, one trillion miles long, has been identified feeding into the triple-star system GW Orionis, located 1,500 light-years away.
• This gas flow is identified as the likely cause of the misalignment found between the rings of the system's circumtrinary protoplanetary disk.
• Observations using the Atacama Large Millimeter/submillimeter Array (ALMA) provided critical data linking the system's ongoing accretion to its unique disk structure.

The GW Orionis Disk Misalignment

• The system features three distinct dust rings, each tilted at different angles, with a significant discrepancy between the innermost and outermost rings.
• Researchers modeled the trajectory of the gas streamer using CO isotopologues (12CO for extent and velocity; 13CO for density).
• Findings show the streamer’s angular momentum vector aligns within ~3° of the outermost ring, suggesting it acts as the driver for the observed ~32° misalignment with the inner rings.

Implications for Star Formation

• The research challenges the traditional model of isolated star formation, demonstrating that chaotic, uneven gas streams are active participants in shaping planetary environments.
• These streamers may explain various anomalies, such as unexpected chemical signatures, metallicity variations, and pronounced orbital tilts in other solar systems.
• Evidence suggests the system is currently in the late stages of infall, as the accretion rate is slowing.

Future Research

• Astronomers aim to conduct a systematic survey of young stellar systems to determine how common these streamers are.
• Future observations will focus on shock tracers to pinpoint the exact impact site of the streamers on the disks and confirm their role in the diversity of planetary system architectures.