https://phys.org/news/2020-11-solar-years.html Solar system formed in less than 200,000 years by Anne M Stark, Lawrence Livermore National Laboratory Please Register or Log in to view the hidden image! Artist's conception of the dust and gas surrounding a newly formed planetary system. Credit: NASA. A long time ago—roughly 4.5 billion years—our sun and solar system formed over the short time span of 200,000 years. That is the conclusion of a group of Lawrence Livermore National Laboratory (LLNL) scientists after looking at isotopes of the element molybdenum found on meteorites. more at link.............. the paper: https://science.sciencemag.org/content/370/6518/837 Astronomical context of Solar System formation from molybdenum isotopes in meteorite inclusions: Timing Solar System formation The oldest solids that formed in the Solar System are calcium-aluminium–rich inclusions (CAIs), small metallic droplets that were later incorporated into meteorites. The ages of CAIs are conventionally taken as the age of the Solar System, but which exact moment in star formation they correspond to has been unclear. Brennecka et al. measured molybdenum isotope ratios in CAIs and found a wide range of origins in both the inner and outer Solar System. They propose that CAIs formed from heterogeneous material accreting from the presolar nebula and that the ages of CAIs coincide with the Sun's transition from a protostar to a pre–main sequence star. Science, this issue p. 837 Abstract Calcium-aluminum–rich inclusions (CAIs) in meteorites are the first solids to have formed in the Solar System, defining the epoch of its birth on an absolute time scale. This provides a link between astronomical observations of star formation and cosmochemical studies of Solar System formation. We show that the distinct molybdenum isotopic compositions of CAIs cover almost the entire compositional range of material that formed in the protoplanetary disk. We propose that CAIs formed while the Sun was in transition from the protostellar to pre–main sequence (T Tauri) phase of star formation, placing Solar System formation within an astronomical context. Our results imply that the bulk of the material that formed the Sun and Solar System accreted within the CAI-forming epoch, which lasted less than 200,000 years.
It's not so much about the consolidation of planetary/stellar accretions, as about the time frame. The previous data told cosmologists that gravity took millions of years for a star to form and planets beyond that. 200,000 years if further validated, is a big refinement.
I don't think that's what they are saying. I couldn't read the whole article (without paying) but my impression was that this 200,000 year range was after the protostar had formed (and that could be millions of years) and before the planets could be considered as fully formed. I think the planets are mostly formed from the same accretion disc as the Sun and the period just before the protostar becomes a main sequence star to the point the planets have fully formed and cleared out their orbits is now thought to be 200,000. Am I wrong?
Hmmm I'll quote/highlight two parts..... "They propose that CAIs formed from heterogeneous material accreting from the presolar nebula and that the ages of CAIs coincide with the Sun's transition from a protostar to a pre–main sequence star." and Abstract Calcium-aluminum–rich inclusions (CAIs) in meteorites are the first solids to have formed in the Solar System, defining the epoch of its birth on an absolute time scale. This provides a link between astronomical observations of star formation and cosmochemical studies of Solar System formation. We show that the distinct molybdenum isotopic compositions of CAIs cover almost the entire compositional range of material that formed in the protoplanetary disk. We propose that CAIs formed while the Sun was in transition from the protostellar to pre–main sequence (T Tauri) phase of star formation, placing Solar System formation within an astronomical context. Our results imply that the bulk of the material that formed the Sun and Solar System accreted within the CAI-forming epoch, which lasted less than 200,000 years. :::::::::::::::::::::::::::::::::::::::: Obviously we are unable to go beyond that pay wall, but I find those parts relavent and reasonably explanatory. Perhaps someone else may like to assist and interprete?
Also from the article................ https://phys.org/news/2020-11-solar-years.html "Previously, the timeframe of formation was not really known for our solar system," said LLNL cosmochemist Greg Brennecka, lead author of a paper appearing in Science. "This work shows that this collapse, which led to the formation of the solar system, happened very quickly, in less than 200,000 years. If we scale this all to a human lifespan, formation of the solar system would compare to pregnancy lasting about 12 hours instead of nine months. This was a rapid process." The oldest dated solids in the solar system are calcium-aluminum–rich inclusions (CAIs), and these samples provide a direct record of solar system formation. These micrometer- to centimeter-sized inclusions in meteorites formed in a high-temperature environment (more than 1,300 Kelvin), probably near the young sun. They were then transported outward to the region where carbonaceous chondrite meteorites (and their parent bodies) formed, where they are found today. The majority of CAIs formed 4.567 billion years ago, over a period of about 40,000 to 200,000 years. ::::::::::::::::::::::::::::::::::::::: Perhaps poor journalism, as the red highlighted part seems to be saying what you think and apparently contradictory to the other part....
No one else commenting on this? You may well be right. Irrespective it certainly is more evidence for the stellar/planetary collapse accretion disk method, [as we have seen in many systems] with gravity as the great universal shaper.
