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Star systems such as our own form within interstellar clouds of gas and dust that collapse producing young stars surrounded by protoplanetary disks. Planets form within these protoplanetary disks, leaving clear gaps, which have recently been observed in evolved systems when the mother cloud was eliminated.
ALMA has now revealed an evolved protoplanetary disk with ample space still being fed by the surrounding cloud via large accretion strands. This shows that the accretion of material on the protoplanetary disk is continuing for longer than previously thought, influencing the evolution of the future planetary system.
A team of astronomers led by Dr Felipe Alves of the Center for Astrochemical Studies (CAS) at the Max Planck Institute for Extraterrestrial Physics (MPE) used the Atacama Large Millimeter / submillimeter Array (ALMA) to study the accretion process in the object. stellar [BHB2007] 1, a system located at the tip of the Pipe Molecular Cloud.
The data from ALMA reveals a disk of dust and gas around the protostar and large filaments of gas around this disk. Scientists interpret these filaments as accretion streamers that feed the disc with material extracted from the environmental cloud.
The disk reprocesses the accumulated material, delivering it to the protostar. The observed structure is very unusual for stellar objects at this stage of evolution – with an estimated age of 1,000,000 years – when circumstellar disks have already formed and matured for the formation of planets.
“We were quite surprised to see such prominent accretion strands falling into the disc,” Alves said. ‘The activity of the accretion strand shows that the disc is still growing while simultaneously feeding the protostar.’
The team also reports the presence of a huge cavity inside the disc. The cavity is 70 astronomical units wide and includes a compact zone of hot molecular gas. Additionally, supplemental radio frequency data from the Very Large Array (VLA) indicate the existence of non-thermal emissions at the same point where the hot gas was detected.
These two lines of evidence indicate that a substellar object – a young giant planet or a brown dwarf – is present within the cavity. As this companion accretes material from the disk, it heats the gas and possibly powers strong ionized winds and / or jets. The team estimates that an object with a mass between 4 and 70 masses of Jupiter is needed to produce the observed gap in the disk.
“We present a new case of star and planet formation occurring in tandem,” says Paola Caselli, director of MPE and head of the CAS group.
“Our observations strongly indicate that protoplanetary disks continue to accumulate material even after planet formation has begun. This is important because fresh material falling on the disk will affect both the chemical composition of the future planetary system and the dynamic evolution of the planet. ‘entire disc “.
These observations also pose new time constraints for planet formation and disk evolution, shedding light on how star systems like ours are sculpted from the original cloud.
Research Report: “A case of simultaneous formation of stars and planets”
Related links
Max Planck Institute for Extraterrestrial Physics
Lands Beyond Beyond – extra solar planets – news and science
Life beyond the Earth
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A planet of earth mass on the run?
Washington DC (SPX) November 22, 2020
Scientists have long believed that there could be billions to trillions of anomalous planets wandering through our galaxy, not attached to any host stars. A recent study has now identified one such candidate, potentially the first land-mass world we have spotted on the run. We have discovered more than 4,000 exoplanets over the past three decades, covering a dramatic range of masses, sizes, temperatures, compositions, orbital properties, and more. The vast majority of them, however, share one characteristic: the … read more
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