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Telescopes

ASTRON is responsible for the operations of the Westerbork Synthesis Radio Telescope (WSRT) and the Low Frequency Array (LOFAR).

Astronomy

The astronomical research at ASTRON is closely aligned with the strengths of our facilities LOFAR and WSRT-APERTIF.

Diversity & Sustainability

ASTRON is committed to achieving a fair, welcoming, and sustainable work environment for all.

Beschermingszones


Met onze radiotelescopen nemen wij de meest zwakke signalen uit het heelal waar. Daardoor zijn zij kwetsbaar voor elektromagnetische storing. Met het tijdig treffen van de juiste maatregelen kan storing worden voorkomen.

Wireless Data Lab


Draadloze techniek lijkt vanzelfsprekend, maar de ontwikkeling ervan gaat niet vanzelf. Daarom hebben we bij ASTRON een proeftuin ingericht; het Wireless Data Lab.

Making discoveries
in radio astronomy
happen.

ASTRON is the Netherlands Institute for Radio Astronomy, and is part of the Institutes organisation of NWO.
STORIES

Exoplanet Sparks Stellar Fireworks

Astronomers have witnessed a planet causing storms to erupt on its parent star, a discovery that could reshape our understanding of how planets and stars interact and evolve together. These findings are published today in the scientific journal Nature.

Astronomy
Uncategorized
Published by the editorial team, 2 July 2025

New ‘mini halo’ discovery deepens our understanding of how the early Universe was formed

Astronomers have uncovered a vast cloud of energetic particles – a ‘mini halo’ – surrounding one of the most distant galaxy clusters ever observed, using the LOFAR radio telescope, marking a major step forward in understanding the hidden forces that shape the cosmos.

LOFAR
News
Published by the editorial team, 27 June 2025

An Earth-sized radio observatory just got better: South Africa’s MeerKAT telescope joins forces with the European VLBI Network of telescopes

South Africa’s MeerKAT radio telescope has successfully conducted very long baseline interferometry (VLBI) observations with telescopes of the European VLBI Network (EVN)—currently the world’s most sensitive VLBI network. Their synergy sets a new standard for global collaboration and significantly enhances both resolution and sensitivity, opening new avenues for scientific exploration.

News
WSRT-APERTIF
Published by the editorial team, 10 June 2025

All sky, all the time – A new radio sky monitor for transients and technosignatures

Breakthrough Listen, headquartered at the University of Oxford – the most ambitious project to date searching for technosignatures (signs of technology as an indicator of extraterrestrial intelligence) – is partnering with ASTRON, the Netherlands Institute for Radio Astronomy, and the University of Manchester, to deploy a new all-sky monitor at the Westerbork Observatory in the Netherlands. The new experiment takes phased array feeds (PAFs) – essentially wide-field radio cameras – that were previously deployed on the Westerbork Synthesis Radio Telescope (WSRT), and installs them on the ground, looking up at the sky directly.

WSRT-APERTIF
Published by the editorial team, 12 May 2025
DAILY IMAGE

Towards an automated search for variable sources

© Apache 2.0

Timo Millenaar & Antonia Rowlinson

The search for transient or otherwise variable sources over long time scales (seconds to years) requires the scouring of many astronomical images. This is what the original transients pipeline [1] does. It finds sources in images and relates them to sources found in previous images, in order to create lightcurves and detect new sources. This approach is described in the TraP paper [2].

Since this methodology has yielded useful scientific results, it is being scaled up. The aim is to apply this methodology to the majority of the LOFAR 2.0 programs (constrained by embargoed data and consensus). Freshly observed LOFAR 2.0 data will then be processed by the transients pipeline, continuously building out lightcurves and looking for new sources. This requires the reworking of the original software package, in order to keep up with the large amounts of data we expect to process. Version 1.0.0 of this new software [3] has recently been released, which means researchers can now deploy this on their own machines to process the data quicker and at a larger scale. Next efforts will make the new version more feature complete and even faster. The biggest challenge though, will now be to integrate the software into the SDC such that it runs automatically on all suitable data.

In the image at the top a visualization is shown that is based on the database created by the new version of TraP. For each source two metrics are calculated that are a measure of flux variability over time of a single source. These two metrics are visualized in a scatter plot where we are mostly interested in sources that are highly variable on both metrics, i.e. the upper right corner. The lightcurve and the location of the source (in the most recent image) are shown for one of the variable sources.

1. Gijs J. Molenaar, John D. Swinbank. Transients pipeline. 2012. URL: https://github.com/transientskp/tkp/tree/master

2. John D. Swinbank et al. “The LOFAR Transients Pipeline”. In: Astronomy and Computing 11 (2015), pp. 25–48. issn: 2213-1337. doi: https://doi.org/10.1016/j.ascom.2015.03.002. url: https://www.sciencedirect.com/science/article/pii/S2213133715000207.

3. Timo Millenaar. Transients pipeline. 2025. URL: https://git.astron.nl/RD/trap

ASTRON daily image.
EVENTS

CASPER Workshop 2025

Mon 08 Sep 2025 - Fri 12 Sep 2025

The CASPER workshop is a semi-annual workshop where FPGA, GPU, and general heterogeneous system programmers get together to discuss new instruments in radio astronomy, as well as the tools and libraries for developing and manipulating these instruments.

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