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 Žagare May 29, 2026
Ventspils University of Applied Sciences has officially adopted the COLOURS Alliance EDI Policy – a shared framework for equality, diversity and inclusion. The policy will now be adapted and implemented within the university’s operations. The aim is to strengthen inclusion across education, research, and everyday practices. The policy can therefore be seen as both a pedagogical and strategic implementation tool to prevent discrimination, increase understanding of differences, and equip students and staff to perform at their best in diverse teams. EDI stands for equality, diversity and inclusion. The training in EDI is designed to strengthen interpersonal relationships, raise awareness of the value of diversity in innovation, creativity and knowledge development, and encourage reflection on one’s own position and approach to others. The implementation of the policy contributes to the development of generic competences and critical thinking among both students and staff. This EDI policy is part of a much larger context, as we are one of nine higher education institutions in Europe adopting the same framework. EDI as a driver for an inclusive society The policy also emphasizes the importance of collaboration through the Quadruple Helix model, where universities, industry, the public sector, and civil society work together. The goal is not only to develop knowledge within EDI, but also to disseminate it and create societal impact. The policy marks the starting point for new initiatives and serves as a bridge to society. EDI strengthens the quality of education and research and is an important tool for both current operations and future needs. Signed policy is available HERE
By Rota Žagare May 28, 2026
On Tuesday, May 19th, second year students of the bachelor’s study programme “Translation and Language Technologies” participated in a lecture lead by guest lecturer Aurélie Le Melinaidre from the Southern Brittany University in France. She tested the students’ knowledge of various English idioms, encouraged creativity by asking them to rewrite a text fragment as differently as they could, and was pleasantly surprised by the students’ excellent knowledge of English. Students also learned about the guest lecturer’s experience teaching English in different countries. Guest lectures held on May 20th and 21st were led by guest lecturer Karolina Siwek from Jan Dlugosz University in Poland. The guest lecturer, met through the COLOURS network, gave four interconnected lectures about different translation aspects for the second- and third-year students of the bachelor’s study programme “Translation and Language Technologies”. Karolina Siwek firstly introduced the students to the history of translation, compared what the profession of a translator was like in the 19th and 20th centuries and what it is like today, highlighting the aspects that have remained the same and those that have changed. During Wednesday’s lecture, students had the opportunity to engage in a discussion and compare the nature of the profession, not only from a historical perspective, but also in terms of the current state of the translation industry in Poland and Latvia. During the lecture about the differences between literary and specialised translators, the guest lecturer compared the translator’s visibility in their work, various potential risks during translation, and the necessary skills, as well as discussed about the prestige and income of the profession. Particular attention was paid to hybrid competencies, which play a significant role in the modern translation profession. Meanwhile, on Thursday, a series of related lectures took place about ISO standards and their impact on the daily work of translators, covering both the positive and negative aspects. The guest lecturer also discussed possible emotions of a translator, their causes, and how to manage them, emphasizing, above all, that emotional regulation is a core professional skill for translators. The guest lecturer shared several stories about her experiences, describing how she handled specific situations and what she learned from them, giving the students a realistic insight into the profession of translation and offering useful advice. Prepared by Sanija Zundovska and Sindija Plotniece from the study programme “Translation and Language Technologies”
By Rota Žagare May 19, 2026
Three students from Ventspils University of Applied Sciences participated in the student networking event “Meet the Nordics: Insights, career opportunities and networking”, organized by the Nordic Council of Ministers’ Office in Latvia in Riga. The event was organized in cooperation with the embassies of Denmark, Finland, Norway, and Sweden the event brought together students from different universities to explore diplomacy, Nordic-Baltic cooperation, and international career opportunities. Throughout the event, students gained valuable insight into the daily work of diplomats, the challenges of working in international environments, and the skills needed to succeed in diplomacy. The speakers shared not only professional experience, but also personal stories about communication, adaptability, and building a meaningful career in an ever-changing global environment. Second-year student of the bachelor’s study programme “Intercultural Communication”, Luīze Anna Spriņģe , highlighted the networking session as the most memorable part of the event: “This part was the most valuable because we could learn more directly from the professionals and their experience. It was valuable to speak with diplomats in a more open environment where we felt comfortable asking different questions.” She also admitted that it was especially interesting to hear the advice of Norwegian Ambassador Ine Måreng, Finnish Deputy Head of Mission Eero Vento, and Danish Deputy Head of Mission Alexander Lemche on how to stand out professionally and build a career in diplomacy. Additionally, second-year student of the bachelor’s study programme “Intercultural Communication”, Evija Saldaka , emphasized the practical value of the experience: “It was interesting to hear about different career paths and practical examples from the diplomats’ daily work. The networking conversations felt especially useful.” Meanwhile, first-year student of the bachelor’s study programme “Translation and Language Technologies”, Janita Kate Asare , shared that the event gave her a deeper understanding of the responsibility and complexity of diplomatic work. She especially appreciated the discussions about diplomacy, work-life balance, and maintaining professionalism in international environments. The students agreed that international events like this provide much more than new knowledge. They create opportunities to develop communication skills, build meaningful professional connections, and inspire students to think more boldly about their future careers. The event also highlighted that diplomacy is not only about politics or international agreements, but equally about building understanding, trust, and dialogue between people and cultures. Written by: Elizabete Apiņa-Fleisa (BSP “Intercultural Communication”, 1st year)
By Rota Žagare May 14, 2026
On May 6, Ventspils University of Applied Sciences hosted its annual Culture Day event, this year titled “Between Respect and Mistake”, organized by 1st-year students of the Bachelor’s study programme “Intercultural Communication”. The event brought together more than 54 local and international students and lecturers in a shared exchange of cultures and experiences. During the event, participants had the opportunity to explore the traditions, social norms, and cultural differences of Croatia, Ukraine, Germany, India, Ghana, and Latvia through interactive presentations and activities. Students shared personal experiences, engaged in dialogue with the audience, and encouraged participants to reflect on the importance of respect, understanding, and the ability to adapt to different cultural environments in everyday communication. This year, the event was also organized as an international initiative within the COLOURS Alliance, involving students and participants from various European universities. A special contribution was made by representatives from Croatia, who introduced the social norms, etiquette principles, and common cultural misunderstandings of their culture. The event was also accessible online, allowing the international audience to participate in activities and cultural exchange regardless of location. An essential part of the event was the “Flavor of My Culture” table, where participants shared traditional dishes and snacks representing their cultures. The atmosphere throughout the event was characterized by openness, curiosity, and a genuine willingness to learn about one another beyond familiar boundaries. Culture Day once again demonstrated that intercultural communication is not only about simply speaking to one another — it is about the ability to listen, understand, accept, and most importantly, build connections between people with different experiences and worldviews. Events like these strengthen the international environment of Ventspils University of Applied Sciences, foster a stronger sense of community, and highlight the importance of cultural diversity both within the university and in society as a whole. Prepared by: Elizabete Apiņa-Fleisa Bachelor’s study programme “Intercultural Communication”, Year 1
By Rota Žagare May 6, 2026
The modern work environment is undergoing rapid change, and companies are increasingly seeking solutions to improve employee well-being. Last week, the hackathon “Workplace Reinvented” took place at Ventspils University of Applied Sciences, where over three days students developed solutions to challenges posed by companies from Ventspils, focusing on strengthening employees’ physical and mental health. During the hackathon, inspiring lectures were delivered by “Vesels Birojs” founder Laima Buša, director of Ventspils Music High School Jēkabs Macpans, and public speaking specialist Rūta Maltisova. At the end of the hackathon, students presented their ideas, which were evaluated by a jury. The three best teams were awarded a total prize fund of €2,000: 1st place and €1,000 went to the team “Slippies” with their solution “Pawse” – a service providing regular dog visits to offices, carried out by trusted and experienced dog walkers. Such visits were intended to improve well-being in the workplace, resulting in higher work efficiency. 2nd place and €600 went to the team “Taij” with an idea of integrating treadmills into the work environment, emphasizing that this solution could improve employees’ concentration, decision-making, and reduce fatigue caused by sedentary work. 3rd place and €400 went to the team “Enviora” , which developed an artificial intelligence office assistant aimed at improving employee well-being. Throughout the hackathon, participant teams were supported by experienced mentors, including Sandra Žukova (head of the regional office of the Investment and Development Agency of Latvia in Ventspils), mentors of the “Startup Management” study program Elviss Brauns and Atis Mertens, and Ventspils Music High School director Jēkabs Macpans. On the second day, mentoring was provided by VUAS HR department head Elīna Feldmane and senior specialist Raitis Didrihsons, head of the Science and Development Department Vitālijs Petkevičs, mentor and lecturer Āris Birze, ASYA customer support team leader and VUAS alumna Marta Anete Vinniņa, and HR WellBe founder Vija Niedre. In addition to developing ideas, participants also had the opportunity to strengthen team spirit and take care of their well-being outside of work sessions. The students visited the Adventure Park in Ventspils, where they tried disc golf and a ride on the toboggan track, and also took part in meditation sessions. The hackathon was supported by Alpro, Paulig, SaltCave, Ventspils Adventure Park, Rimi, and Red Bull. The event was implemented within the COLOURS European University Alliance, bringing together students from Latvia as well as partner universities in Italy and Germany. More photos are available HERE Ventspils Augstskolas Hackathon "Workplace reinvented" Password: ventspils2026
By Rota Žagare May 5, 2026
We invite YOU to another cozy TEA & TALKS afternoon! This time we will talk about May 4th "Day of the Restauration of the Republic of Latvia" and why it is so important for Latvia! We will also make a traditional Latvian dish - so make sure to keep your afternoon free to not miss out on valuable insights and food! As always, you are welcome to bring snacks and your cup as there will be tea! Everybody is welcome to join! Where & when? Date: 7th May 2026 Time: 17:00 Place: D0 We are looking forward to seeing you and your friends!
Other news