Metsähovi Radio Observatory Open data

Aalto University Metsähovi Radio Observatory (MRO) is the only radio astronomical observatory in Finland.

The primary instrument is the 14-metre radio telescope, used mainly for observing the Sun, active galaxies and microquasars, and for international very long baseline interferometry (VLBI) campaigns. The radio telescope is enclosed by a radome that protects the equipment from the weather and the Sun’s heat radiation, making it possible to point the telescope at the Sun without affecting the sensitive receivers.

Observations are carried out on "24/7/365" basis, and observing time is scheduled for 98 % of the hours of the year. Other instruments include various radio telescope (diameters 5.5, 1.8 and 1.1 metres) and various other kinds of radio antennae.

Data gathered at MRO are open, with few exceptions. We have several ongoing projects aiming at making the data public and easily accessible while taking into account security and data transfer concerns. Currently, the AGN data can be viewed online (and requested separately), and the solar dataset is being published on an external reposity. If you are interested in the various data Metsähovi manages, contact:


Four decades of solar radio observations

Radio map at 37 GHz.

The year 2018 marked the 40th anniversary of solar radio observations at Aalto University Metsähovi Radio Observatory. The observatory’s 14-metre radio telescope has been used to create solar radio intensity maps mainly at 37 GHz since 1978; additionally, a 1.8-metre radio telescope has been monitoring the total brightness of the Sun at 11.2 GHz since 2000, and a 1.1-m telescope at 5.5 GHz was taken into use in 2019. Furthermore, various antennas for recording solar flare spectra at frequency range 16-850 MHz have been online for several years.

These data are available online via the Fairdata service provided by CSC – Finnish IT center for science, and the Ministry of Education and Culture (more info here).

The data at is in .zip archives and downloadable either by month or year (and for separate instruments), or as a whole. Even in compressed form the data take some 800 GB (with over 150 GB added every year), but you can first download only pictures, and later those parts of the data you need. Below are also links to websites where you can browse plotted data in order to find interesting days/months/years, and only download those files. New data are added to the dataset once a month.


Nearly forty years of active galactic nuclei monitoring

Lightcurve of the quasar 3C279 at 37 GHz.

The 14-m radio telescope is used to observe hundreds of active galactic nuclei (AGN) and a few galactic microquasars at 37 GHz and 22 GHz daily. Long observational time-series are needed because due to their immense size, active galaxies evolve very slowly, often taking years or even decades to complete a huge outburst.

Metsähovi's AGN and microquasar monitoring has been active since early 1980s. Our source list with quicklook data is available through the following link; instructions for obtaining the actual data for a given source is also given on the linked page.