How Special Are We? New Clues to the Formation of Our Solar System
The nearby star formation region provides clues to the formation of our solar system.
The radioactive elements could have been blown onto the nascent solar system by a nearby exploding star (a supernova) or by the strong stellar winds of a massive star known as the Wolf-Rayet star. The presence of radioactive material at the birth of the solar system has been a huge mystery for the past 50 years. Does the formation of planetary systems like ours require a Goldilocks situation, not too close, not too far from a source of radioactive material?
The authors of the new study used multi-wavelength observations of the Ophiuchus star-forming region, including spectacular new infrared data from the Vienna-led VISIONS Survey, currently on
“> THAT Surveying telescope in the Chilean desert that reveals the interactions between the clouds of star-forming gas and radionuclides produced in the next cluster of young stars. Their results suggest that supernovae in the previous generation of stars are the most likely source of short-lived radionuclides in the star formation clouds.
“Our solar system was most likely formed in a huge molecular cloud along with a young star cluster, and one or more supernova events from some massive stars in this cluster contaminated the gas that turned into the sun and its planetary system,” says co-author Douglas NC Lin from UC Santa Cruz. “While this scenario was in the past, the strength of this paper is that it uses multiple wavelength observations and sophisticated statistical analysis to derive a quantitative measure of the likelihood of the model.”
The Ophiuchus cloud complex contains many dense protostellar nuclei in various stages of star formation and protoplanetary disk evolution, which represent the earliest stages in the formation of a planetary system. By combining image data in the wavelength range from millimeters to gamma rays, the researchers were able to visualize an aluminum-26 flow from the nearby star cluster towards the Ophiuchus star-forming region.
“The enrichment process we see in Ophiuchus is consistent with what happened during the formation of the solar system 5 billion years ago,” says John C. Forbes. “When we saw this beautiful example of how the process might go, we tried to model the nearby star cluster that produced the radionuclides we see today in gamma rays. We now have enough information to say that there is a 59 percent chance of supernovae and a 68 percent chance that it came from multiple sources rather than just one, ”says Forbes.
This type of statistical analysis assigns probabilities to scenarios that astronomers have debated over the past 50 years, Lin notes. “This is the new direction for astronomy to quantify probability,” he says.
“Ophiuchus as a star-forming region is nothing special,” says João Alves from the University of Vienna. “This is just a typical configuration of gas and young massive stars, so our results should be representative of the accumulation of short-lived radioactive elements in star and planet formation throughout
“> Milky Way. We’re not that special, and we should expect many other solar systems, like our own, which swims in the Milky Way. “
The new findings also show that the amount of short-lived radionuclides that are incorporated into newly emerging star systems can vary widely. “Many new star systems are born with aluminum-26 abundances in line with our solar system, but the variation is huge – several orders of magnitude,” says Forbes. “This is important for the early development of planetary systems, since aluminum-26 is the most important early heat source. More aluminum-26 probably means drier planets. “
The team also used data from the European Southern Observatory VISTA Telescope, the Herschel Space Observatory of the European Space Agency (ESA), the Planck satellite of the ESA and
“> NASACompton’s Gamma Ray Observatory.
Reference: “A Solar System formation analog in the Ophiuchus star-forming complex” by John C. Forbes, João Alves and Douglas NC Lin, August 16, 2021, Nature Astronomy.
DOI: 10.1038 / s41550-021-01442-9