Spiral arm high-mass protostellar accretion disk revealed by radio telescopes

February 28, 2023

Spiral arm high-mass protostellar accretion disk revealed by radio telescopes

High-mass stars are 8 or more times more massive than the Sun. They act like atomic factories to generate many of the necessary building blocks for life and technology in the universe and they alter the appearance and evolution of galaxies. The massive stars “die” spectacularly as supernova explosions, while their brightness overshine the rest of the galaxy.

 

Despite their importance in the Universe, the process by which high-mass stars are born has been a mystery for many decades. It has recently become known that they form at the hearts of rotating disks of gas and dust, known as protostellar disks, which are ~1000 AU radius (that is, ~1000 times the distance at which the Earth orbits the Sun).

 

One theory which is emerging as a front runner in high-mass star formation research is the idea of ‘episodic accretion’ where by clumps of dusty gas occasionally fall from the protostellar disk onto the growing star, or ‘protostar’, at the centre. However, these growth bursts occur on timescales of hundreds of years, and, lasting only a few months, and are very rare events to witness. To date, astronomers have only witnessed a three growth bursts in high-mass protostars. The most recent, and the most intensely investigated was the 2019 growth burst in high-mass protostar G358-MM1.

 

The episodic accretion theory proposes that protostellar disks are clumpy and that spiral arms may emerge in the disk due to it experiencing the pull of its own self-gravity. Observing protostellar disks around high-mass protostars, let alone any spiral structure or clumpiness, has been a challenge for astronomers. Such disks, and their high-mass protostars, form inside dense clouds of gas and dust in turbulent stellar nurseries, which are for the most part invisible to conventional optical telescopes.

 

However, in a new Nature Astronomy publication https://www.nature.com/articles/s41550-023-01899-w

 

A team of astronomers who specialize in ‘maser’ emission - which is a microwave wavelength laser - were able to map a high-mass protostellar disk in higher detail than was achieved before. Using Very Long Baseline Interferometry (VLBI) arrays from around the world in an international collaboration, the team were able to discover spiral arms in the rotating disk of high-mass protostar, G358- MM1. This is the very same protostar which was seen to experience a growth burst in 2019.

 

The team used a new technique called ‘heat-wave mapping’ which used the growth burst’s own flash of radiation to map the surface of the disk using methanol masers. In total, 25 radio telescopes were used, from Ocean, Asia, Europe and America. All data were combined to produce an image of the G358-MM1 spiral disk with milliarcsecond (1/3600000th of a degree) resolution. In everyday terms it is equal to reading a newspaper 8 km away.

 

The discovery brings together evidence of several of the aspects of episodic accretion theory: a rotating disk, growth bursts, and spiral structure which helps to feed the growing high-mass protostar.

 

The team will continue to search for growth bursts in high-mass protostars, using a global cooperative of traditional radio telescopes, called the Maser Monitoring Organisation (M2O). So far, only 3 high-mass protostellar bursts have been seen, the team hopes to find many more to explore more growth bursts in other high-mass protostars.

 

G358-MM1 has four spiral arms which wrap beautifully around the protostar. The spiral arms help to feed disk material down to the centre of the system where it can reach the protostar and feed it.


In this study Ventspils University of Applied Sciences was represented by Ventspils International Radio Astronomy Center (VIRAC) Researcher Artis Aberfelds.

We would like to add that principal investigator of this research Ross Alexander Burns joined VIRAC as Lead-guest researcher starting from January 2023.

Our infrastructure joined this research as part of EVN.

Share on other platforms

Other news

By Rota Rulle July 4, 2025
The planets of the Solar System formed from fine interstellar dust particles. As the interstellar cloud (which would later become the Solar System) condensed, the dust particles gradually sticked together. As this process continued in the disk around the proto-Sun, they grew to the size of sand grains, peas, beans, pebbles, etc., until the “dust” the size of flying mountains continued growing by attracting material with their own gravity.
By Rota Rulle June 27, 2025
Ventspils University of Applied Sciences is a regional university of applied sciences where scientific activities are carried out in three strategic specialization areas: In natural sciences – implementing research in the fields of mathematical modelling, optical signal technology, astronomy and astrophysics, space technology and engineering electronics, ICT and electronics In social sciences – conducting research in the areas of entrepreneurship, innovation, and regional economics In the humanities – conducting research in applied linguistics, comparative linguistics, and translation studies In June 2025, the science communication brand researchLatvia paid special attention to the contribution of Ventspils University of Applied Sciences to research activities, emphasising the contribution of Mg. sc. comp. Karina Šķirmante, researcher and lecturer at the Ventspils International Radio Astronomy Centre, to science, technology and astronomy. Ventspils University of Applied Sciences – a university with the largest radio telescope antenna in Northern Europe Although Ventspils University of Applied Sciences will only be 28 years old this year, for most of its existence, it has been home to a world-class research centre – the Ventspils International Radio Astronomy Centre (VSRC). Ventspils University of Applied Sciences has been home to the largest radio telescope antenna in Northern Europe for 21 years. " If the world stands on three pillars, then VeA has four – three faculties and the VSRC. Science is inseparable from education, and higher education must be grounded in scientific principles. It is this close connection between education and science that has ensured the rapid development of VSRC and the Irbene radio telescope complex over the past 20 years. More than 150 students have developed their bachelor's or master's theses at VSRC - either in science or technology development. The majority of VSRC employees are graduates of our university. VSRC has grown into one of the leading scientific institutions in Northern Europe, specialising in astrophysics and space technologies. VSRC conducts international-level scientific research and contributes to technological innovations, bringing Latvia's name to the world. Shortly, radio telescopes will also be used in a completely new direction - in satellite communications, communicating with space satellites near the Moon," says Andris Vaivads , rector of Ventspils University of Applied Sciences. International partners highly value VeA's infrastructure – the radio telescope complex in Irbene is part of the European radio telescope networks (JIVE, ILT) with significant importance in scientific observations. VeA's scientific activities are focused on internationally significant research in collaboration with international partners, including the Swedish Space Corporation and the European Space Agency. In 2024, Ventspils University of Applied Sciences produced 41 publications indexed in Scopus and Web of Science, of which 17 were published in the highest-ranked journals in Q1, and four in Q2. This is an excellent indicator indicating competitive and high-quality research. New researchers are being trained Many employees of the VSRC and the Faculty of Information Technologies work in both structural units, ensuring effective knowledge transfer between researchers and students. Representatives of this field are actively involved in public education throughout Latvia, conducting practical classes in schools and VeA laboratories, as well as giving lectures at the School of Astronomy. The development of a stratospheric probe by third-year students has also become a tradition, attracting public attention and inspiring future researchers. Ventspils University of Applied Sciences students – the most capable young specialists This July, Mārtiņš Leimants , a student in the "Electronics Engineering" study program, will travel to the Dutch city of Noordwijk to start working at the European Space Research and Technology Centre. Mārtiņš is the second Ventspils University of Applied Sciences student to intern at the European Space Agency (ESA) – a place where only the most capable young specialists from around the world have the opportunity to gain experience. In 2022, Rodrigo Laurinovičs went to ESA and spent two years there. If one student at ESA is a significant achievement and recognition, then two already mark a notable trend, confirming the excellence of our study program. Doctoral studies There are currently 22 doctoral students studying and conducting research at Ventspils University of Applied Sciences – 14 students are obtaining a doctorate in social sciences, and eight students in humanities and arts. The Ventspils International Radio Astronomy Centre is a significant research centre that attracts doctoral students and candidates from other universities conducting research in the field of natural sciences. In the 2023/2024 academic year, the first three graduates of the study program "Economics and Entrepreneurship" received their Doctor of Science degrees at Ventspils University of Applied Sciences. Research funding doubled in 2024 Ventspils University of Applied Sciences and the VSRC are actively involved in various international programs and projects. Since 2024, Ventspils University of Applied Sciences has been part of the European university alliance COLOURS, which unites European regional universities from nine countries: France, Spain, Italy, Germany, Poland, Croatia, North Macedonia, and Sweden. In 2024, the total funding received for research projects reached just under € 2.7 million. This is a significant increase of just under 1.5 million euros compared to 2023. The most significant increase in funding in 2024 is observed in the areas of contract work and intellectual property transfer, demonstrating the university's ability to create practically applicable solutions for industry needs. Ventspils University of Applied Sciences focuses on the creation and transfer of high-value-added knowledge, creating a platform where education, science, and innovation meet. With a clear strategic direction, international vision and modern infrastructure, Ventspils University of Applied Sciences and the Ventspils International Radio Astronomy Centre are an essential part not only in the region and Latvia, but also on a global scale! Video with this month's researchLatvia calendar scientist Mg. sc. comp. Karina Šķirmante
By Rota Rulle June 25, 2025
You are kindly invited to attend a scientific seminar that will take place on June 27, 2025 , at Room D407, VeA IZI VSRC . Seminar Programme 10:00 – 11:00 Prof. Valery M. Nakariakov , University of Warwick, UK "A Plasma Orchestra, or Magnetohydrodynamic Waves in the Solar Corona" 11:00 – 12:00 Lunch break 12:00 – 15:00 Scientific seminar “Magnetohydrodynamic Waves in the Solar Corona” as part of the JIV-ERIC National Node Scientific Seminar Series Please confirm your participation by marking your name in the Excel sheet: Participation Sheet You can join in person or online via Google Meet . Google Meet link --- A Plasma Orchestra, or Magnetohydrodynamic Waves in the Solar Corona Valery M Nakariakov (University of Warwick, United Kingdom) The corona of the Sun is the outermost part of the solar atmosphere. The corona is a very hot, fully ionised plasma dominated by the magnetic field. The corona is the birthplace of extreme events of space weather, and a natural laboratory for plasma physics. One of the most fascinated discoveries made with recent high-precision spaceborne imaging telescopes operating in the extreme UV band is the ubiquitous dynamics of the corona in a form of various large-scale wave motions. An example of such an instrument is the Extreme UV imager on the recently launched Solar Orbiter spacecraft. Typical oscillation periods are several minutes, typical wavelengths are tens to hundred thousand kilometres, and typical speeds are from several tens to several thousand kilometres per second, which make the solar coronal waves the largest electromagnetic wave motions resolved simultaneously in time and space, detected in the Universe. The observed waves are confidently interpreted in terms of the magnetohydrodynamic theory. Various plasma structures of the corona support different types of wave modes, allowing for the use of the waves for the plasma diagnostics via the method of magnetohydrodynamic seismology.
By Rota Rulle June 25, 2025
The Erasmus+ program offers the opportunity to participate in an innovative and dynamic learning format – the Blended Intensive Programme (BIP). This format allows both students and staff to explore a specific topic in depth within an international setting, combining virtual learning with a short but intensive five-day on-site component. Students of Ventspils University of Applied Sciences actively take part in these programs – over the past two academic years, 18 students have participated in BIP courses held in Lithuania, Portugal, Spain, and France. From 26 to 30 May, Ventspils University of Applied Sciences hosted its first Erasmus+ Blended Intensive Programme titled “Technology Startup Course”. The course was implemented as part of the “Developing by Experimenting II” module within the “Start-up Management” study program, in cooperation with two COLOURS partner universities – Jan Dlugosz University in Czestochowa (Poland) and University St. Kliment Ohridski Bitola (North Macedonia). During the program, students from Ventspils University collaborated in international teams with peers from Poland, North Macedonia, and Bulgaria to develop innovative, technology-based business ideas. In total, 38 students participated, including 18 international students (six of whom represented COLOURS partner universities), forming 13 project teams. The primary goal of the program was to enhance students' skills in creating innovative, tech-driven business ventures capable of competing in the real-world market. On 30 May, five of the top teams were selected to present their ideas to investors at the TestDevLab headquarters in Riga. The winning team, “SOUNDPACK”, was represented by Ventspils University of Applied Sciences student Ronalds Palacis. The team’s idea focused on using AI to generate fully cohesive, royalty-free sample packs based on natural language prompts, simplifying the workflow for music producers. The Erasmus+ BIP program provided a valuable experience for both students and staff and helped strengthen cooperation with international partner universities. In the next academic year, Ventspils University of Applied Sciences aims to implement two more BIP programs – one for students and one for staff. We encourage all faculties to submit their BIP program ideas by emailing: erasmus@venta.lv
By Rota Rulle June 18, 2025
On June 5, representatives from the Organisation for Economic Cooperation and Development (OECD) and the European Commission visited Ventspils University of Applied Sciences (VUAS) to discuss issues related to the development of academic careers in higher education in Latvia. The purpose of the visit was to gain an understanding of the role, challenges, and opportunities of regional universities, including VUAS, in the implementation of new academic career models. During the meeting, experts met with the university’s management and academic staff to discuss topics such as attracting and retaining academic personnel, career development opportunities, support for professional advancement, and potential collaboration with other institutions in Latvia. The international expert group included Gillian Golden, Project Leader in the OECD Higher Education Policy Team; Thomas Weko, an international higher education expert and researcher at the George Washington Institute of Public Policy (USA); and Kristiāna Egle, a policy analyst in the OECD Higher Education Policy Team. The experts greatly appreciated the opportunity to hear a report from the Executive Director of the Ventspils City Council on the university's role within the city’s ecosystem, the university’s experience and staff perspectives, as well as the opportunity to learn about the university’s development strategies in a regional context. The discussions covered both the challenges and potential solutions that could help improve the development of academic careers in Latvia.
By Rota Rulle June 18, 2025
When Information Technology Meets the Universe Space exploration is becoming increasingly important, expanding humanity’s knowledge of the universe, promoting innovation and technological development, and attracting new talent to science. Her work highlights the importance of combining expertise from various fields to address complex scientific questions. At such a point of cooperation between technology and astronomy is the doctoral candidate Mg. sc. comp. Karina Šķirmante, a leading researcher and lecturer at Ventspils University of Applied Sciences (VeA). Karina’s research activities cover high-performance computing and data processing, focusing on space technology projects. She is actively involved in the European Space Agency’s Comet Interceptor project, which aims to launch a probe in 2029 to study a comet that has never come close to the Sun directly in space for the first time. In preparation for this mission, Karina, together with colleagues from the Ventspils International Radio Astronomy Centre (VSRC) of the Institute of Engineering Sciences of the Estonian Academy of Sciences, is modelling comet activity in the radio frequency band, in collaboration with researchers from the Tartu Observatory (Estonia) and Aalto University (Finland). This international collaboration is helping to develop and calibrate the instruments that will be used during the mission.
Other news