The researchers have determined that young stars release jets of gas, dust, and magnetic energy from their protostellar disks. The magnetic energy constantly enters the developing stars’ disks, and if too much accumulates, the resulting object would produce a stronger magnetic field than any known protostar. These newly discovered magnetic energy releases, also known as ‘sneezes,’ could play a crucial role in the formation of stars. Kyushu University researchers used the ALMA telescope to gain new insights into this important aspect of star development.HTML telescope in Chile, the team found that in its early stages, the protostellar disk that envelops a newborn star releases bursts of dust, gas, and electromagnetic energy. These bursts, which the researchers refer to as ‘sneezes,’ release the magnetic flux within the protostellar disk and may play a crucial role in the formation of stars. Their discoveries were detailed in The Astrophysical Journal.
Stars, including our Sun, all originate from what are known as stellar nurseries — large accumulations of gas and dust that eventually come together to create a stellar core, or a baby star. Throughout this process, gas and dust form a ring around the star.The baby star is known as the protostellar disk.
“These structures are constantly penetrated by magnetic fields, carrying magnetic flux with them. However, if all of this magnetic flux were retained as the star formed, it would produce magnetic fields much stronger than those observed in any known protostar,” Kazuki Tokuda from Kyushu University’s Faculty of Sciences and the study’s lead author, explains.
As a result, researchers have theorized that there is a process during star formation that would eliminate that magnetic flux. The common belief was that the magnetic field weakened over time.The team focused on exploring the mysterious phenomenon by observing MC 27, a stellar nursery about 450 light-years away from Earth. They used the ALMA array, which is made up of 66 high-precision radio telescopes located 5,000 meters above sea level in northern Chile, to collect their data.
Upon analyzing the data, the team made an unexpected discovery. They found “spike-like” structures extending several astronomical units from the protostellar disk. Further investigation revealed that these spikes were made up of expelled magnetic flux, dust, and gas.okuda. This phenomenon is known as “interchange instability,” where magnetic field instabilities interact with different gas densities in the protostellar disk, causing an outward expulsion of magnetic flux. The researchers likened this to a baby star’s “sneeze” because it resembles the expulsion of dust and air at high speeds.
Furthermore, the team also observed spikes thousands of astronomical units away from the protostellar disk. They speculated that these may be remnants of past “sneezes.”
The team believes that their discoveries will enhance our understanding of the complex processes that mold the formation of stars.The universe continues to capture the interest of both the astronomical community and the public.
“Similar spike-like structures have been observed in other young stars, and it’s becoming a more common astronomical discovery,” concludes Tokuda. “By investigating the conditions that lead to these ‘sneezes’ we hope to expand our understanding of how stars and planets are formed.”
Journal Reference:
- Kazuki Tokuda, Naoto Harada, Mitsuki Omura, Tomoaki Matsumoto, Toshikazu Onishi, Kazuya Saigo, Ayumu Shoshi, Shingo Nozaki, Kengo Tachihara, Naofumi Fukaya, Yasuo Fukui, rnShu-ichiro Inutsuka and Masahiro N. Machida have published an article titled “Discovery of Asymmetric Spike-like Structures of the 10 au Disk around the Very Low-luminosity Protostar Embedded in the Taurus Dense Core MC 27/L1521F with ALMA” in The Astrophysical Journal in 2024. The article is available in volume 965, issue 2, on page 99, with a DOI link: http://dx.doi.org/10.3847/1538-4357/ad2f9a.