On September 23, LOFAR-BG’s Dr. Kamen Kozarev will be guest to a special event organised by RATIO, devoted to the science and technology of the LOFAR telescope and its Bulgarian station. At this free event in Sofia, Dr. Kozarev will talk about LOFAR’s technology and science, its ongoing upgrade, the LOFAR-BG station’s development, and plans for the future. Check out the Facebook event and sign up here: https://www.facebook.com/events/3253103188296459/
In the period 23-28 January, three researchers and one PhD student from IANAO visited ASTRON for a dedicated research meeting on space weather. The observational aspects of both solar and stellar space weather were discussed with the ASTRON experts Dr. Pietro Zucca, Dr. Maaijke Mevius, and Dr. Harish Vedantham. The teams started work on projects ranging from flare observations with LOFAR and other space-based instruments, to the effects of space weather on the Earth’s ionosphere, to stellar flares and their effects on exoplanets. This marks the deepening of scientific collaborations between IANAO and ASTRON in radio astronomy.
Between 13 and 17 December 2021, a team of six IANAO and TUS students and researchers visited ASTRON for a workshop on LOFAR Science Operations. The team learned in detail about the whole process of scheduling and carrying out observations with LOFAR, the subsequent management and processing pipelines for the data, and its archiving. Dr. Marco Iacobelli, Dr. Emmanuela Orru, and Dr. Pietro Zucca led the workshop, which also included tours of the LOFAR control room, exercises in scheduling observations, monitoring their quality, flagging RFI episodes, and a visit to the SURFSara processing center in Groeningen.
The third STELLAR seminar lecture will be by Dr. Harish Vedantham of ASTRON. His online seminar will be held on Tuesday, November 2 2021, at 15:00h CET, over Zoom (connection details below).
“Radio flashes from plasma storms around exoplanets”
Dr. Harish Vedantham
ASTRON, The Netherlands Institute of Radio Astronomy
Watch the video of the Seminar
Low frequency (< few hundred MHz) radio observations uniquely trace several processes that determine the habitability of exoplanets. Coronal plasma ejections that erode planetary atmospheres can be detected using the characteristic radio bursts they emit. Planetary magnetic fields that largely determine the planetary defence against the stellar onslaught can also be detected using radio observations. Radio observations of such phenomena in the solar system are commonplace. I will argue that the extrasolar frontier is now also within reach thanks to powerful new low-frequency telescopes such as LOFAR. I will describe an observational program using LOFAR to systematically survey the low-frequency radio sky for stellar, brown dwarf and exoplanetary emission with unprecedented sensitivities reaching a fraction of a milliJansky at 150 MHz and below. I will present some early successes of this campaign including (a) the discovery of evidence for magnetic interaction between a star and its planet and (b) the discovery of a cold brown dwarf directly in the radio band using its magnetospheric emissions. I will end with an outlook for harnessing radio astronomy’s unique diagnostic capabilities to advance exoplanet science.
About Dr. Vedantham: Staff astronomer, ASTRON & Visiting Assistant Prof. at Univ of Groningen (2018-current); Recipient of Dutch Vidi grant for 2021.
Past affiliations: Millikan fellow at Caltech (2015-2018), PhD University of Groningen (2011-2015).
The third activity of the first period on Work Package 2 was the Digital Signal Processing course part I, presented between 04.10-08.10.2021 by eng. Ronald de Wild, on-site on the campus of the Technical University of Sofia. 10 participants from the Technical University, the Institute of Astronomy, and Sofia University, attended the course and learned the basics of the theory of Signals, Transforms, and Systems.
The DSP course is divided into two modules. In the first part (“Basic DSP”), basic topics on digital signal processing have been treated. The knowledge of DSP at MSc-level treated in the first module will be needed for the second part (“Advanced DSP”).
A list of the topics treated during the course program “Basic DSP”:
Signals (part 1 of 2) classifications; representations; operations
Transforms (part 1 of 3) [Continuous-Time] Fourier Transform
Signals (part 2 of 2) sampling; quantization
Transforms (part 2 of 3) Discrete-Time Fourier Transform (DTFT) & Z-Transform
Systems (part 1 of 3) general: characterization; properties; behavior Systems (part 2 of 3) specific: LTI digital filters: classification; analysis; synthesis
The students have now acquired all the knowledge necessary for the next module of the course!
The second training module for RF techniques and Development [WP2-Task 2] was presented on-site at ASTRON between 27-09-2021 and 01-10-2021 by a team consisting of Michel Arts, Mark Bentum, Juergen Morawietz, Ronald de Wild and Pietro Zucca, on-site at ASTRON. The course was structured in a full week of training including the theory module, practical exercises, and a tour of the facilities at ASTRON, including the LOFAR core and the Westerbork telescope. Seven participants from the Technical University of Sofia attended the course.
The course program “RF Training II” included:
- 4 hours of RF Theory,
- two modules of Hands-On Training of 6 hours,
- visit of the Antenna lab facilities,
- a RF application lecture of 3 hours
- antenna hands on workshop 4 hours
- visit of Telescopes and astronomical applications class 8 hours
A STELLAR Seminar will be delivered online by Dr. Peijin Zhang from the University of Science and Technology of China and the Institute of Astronomy, Bulgarian Academy of Sciences, on Tuesday, August 17, at 15:00h CET.
“Observation, Modeling, and Wave-Propagation Simulations on the Source of Solar Radio Burst”
Dr. Peijin Zhang
University of Science and Technology of China / Institute of Astronomy, Bulgarian Academy of Sciences
The Seminar is free to attend and held online. Find the abstract and connection info at the STELLAR Seminars page.
The next activity of the STELLAR project was the LOFAR Science Workshop, which was held July 26-30, 2021, at ASTRON’s beautiful building near Dwingeloo, The Netherlands. The Bulgarian team, made up of six scientists, PhD and undergraduate students from the Institute of Astronomy (BAS) and two scientists from the Techical University of Sofia, learned about the research done with LOFAR, with an accent on space weather and the Earth’s ionosphere. Tutorials and exercises in processing and analyzing LOFAR data were led by Dr. Pietro Zucca and Dr. Maaijke Mevius. The Bulgarian team had the opportunity to visit the LOFAR core and the Westerbork Synthesis Radio Telescope (WSRT), and enjoyed the cool Dutch summer!
During the Workshop, the visiting team learned about:
1. Long Term Archive (LTA)
Basic query on the LTA. How to search, stage and retrieve the dataset.
2. Processing the beamformed data
Plotting the beamformed data and creating previews of the detasets.
3. Processing interferometric data
Calibration steps and beam/clock corrections.
4. Science visualization of solar data
Plotting the interferometric and beamformed data with the heliocentric coordinate systems and comparison tied array data with interferometric with different baselines.
5. Visit of facilities
Visit of the telescopes and training on the different telescope modes to observe the Sun, the Heliosphere and the ionosphere.
All video recordings of the Space Weather Workshop, organized by DIAS and held online July 12-15, 2021, are now available for free viewing! They can be found at the Workshop website:
They are also available on our STELLAR Lecture Series page.
The first Introduction to Space Weather Workshop of WP4 was held online from 12-15 July 2021. The workshop was hosted by the Dublin Institute for Advanced Studies and Chaired by Dr Shane Maloney and Dr Eoin Carley. The local organising committee also included Dr Sophie Murray and Dr Laura Hayes.
The workshop was advertised primarily to the Bulagrian community associated with the STELLAR project. Registration was via a dedicated workshop webpage (which hosts all video lectures): https://lofar.ie/stellar-sww/
Overall there were 36 registrants to the workshop, consisting of PhD students, Postdocs and early career researchers mainly from Bulgarian institutes but also other countries:
● Institute of Astronomy with NAO – Bulgarian Academy of Sciences (Bulgaria)
● Technical University of Sofia (Bulgaria)
● Naval Academy “N. Vaptsarov” (Bulgaria)
● University of Vienna (Vienna)
● Dublin Institute for Advanced Studies (Ireland)
● Trinity College Dublin (Ireland)
● Egyptian Space Agency (Egypt).
Approximately 1/3 were 3rd level students, 1/3 PhDs and 1/3 with more senior roles.
Talks and speakers:
The workshop consisted of 4 full days of lectures and hand-on sessions. Each day, there were several lectures on space weather from established researchers from the international community. The afternoon sessions each day consisted of hand-on sessions in the use of Python for space weather data analysis. While the entire workshop had a radio science focus, the lectures and hand-on session covered a variety of topics covering radio, X-ray, EUV and white-light observations of the sun, heliosphere, ionosphere and magnetosphere:
● Day 1: An overview of solar physics and space weather science including lectures on an introduction observing the Sun in X-ray and EUV. Speakers: Prof Peter Gallagher, Dr Shane Maloney, Dr Laura Hayes (DIAS).
● Day 2: Solar radio science, including lectures on solar radio bursts, solar radio emission mechanisms and a history of solar radio observing instruments. Speakers: Dr Diana Morosan (University of Helsinki), Dr Eoin Carley (DIAS) and Dr Pietro Zucca (ASTRON). Ms Ciara Maguire, Mr Pearse Murphy, Ms Aoife Ryan (DIAS).
● Day 3: Heliosphere and interplanetary observations, with lectures on white-light observation of coronal mass ejections and observing the heliosphere using interplanetary scintillations. Speakers: Prof Richard Harrison (Rutherford Appleton Labs, STFC-UK), Dr Richard Fallows (ASTRON).
● Day 4: Lectures on space weather operations, magnetospheric science and the ionosphere. The last lecture of the workshop was on the future of space weather science and observations. Speakers: Dr Sophie Murray (DIAS), Dr Laura Hayes (DIAS), Dr Caitriona Jackman (DIAS), Dr Corentin Louis (DIAS) and Dr Nicole Vilmer (Paris Observatory). The last day also dedicated 45 mins to student ‘light-speed’ talks in which 2 students from DIAS and 2 students from IANAO and TUS provided 8 minute talks on their research.
Throughout the 4 days there were 9 female and 10 male speakers, achieving a good gender balance.
Software repositories: The hand-on practical sessions introduced detailed concepts in the use of SunPy for space weather data analysis. It also provided an overview of professional standards in software development including the use of version control via Git and Github. All tutorials were delivered using Jupyter notebook and can be accessed by the workshop Git repository: https://github.com/TCDSolar/STELLAR_SSW_tutorials
Slack Channel: Communication and day-to-day interaction for the workshop was via Slack.
Overall, there were approximately 28 attendees of the workshop including students and researchers from the Bulgarian Academy of Sciences and Technical University of Sofia.