Early EVN observations of transient events
The EVN PC (co-)Chair, following an approval by the EVN CBD Chair, may initiate early observations of transient events in cases where there is a great opportunity to further shorten the gap between the onset of transients and the first observations, and/or the event is expected to have a broad interest by the community. If within two weeks of the first transient report proposals arrive, all teams will have access to the data from these early observations; the data will have the usual proprietary period of 6 months. If there are no proposals within two weeks, the data will be available to any teams per request. Note the EVN may attach additional conditions to releasing these data.
uGMRT in the EVN observations
The Giant Metrewave Radio Telescope (uGMRT, India) now offers time for VLBI observations with the EVN in the 21-cm band, strictly on a best effort basis. Projects requiring uGMRT as part of the EVN should justify this choice in the technical justification part of the proposal (advantages may include improved uv-coverage and resolution, better sensitivity, advanced flux/polarisation calibration strategies, as an example). Read the Call for Proposals for further information.
EVN-lite subarray observations
EVN-lite subarray observations started in February 2023. These provide additional opportunities for trigger projects, outside of the regular disc or e-VLBI sessions. Projects that require a limited EVN sub-array, but flexible triggering, may benefit from this. The dates of EVN-lite observations are listed in the EVN web pages. This is a best-effort service for projects requiring a small number of stations, preferably in the 18-21cm band. Note that the EVN-lite triggers must be received by 8:00 UT 3 days before the observations. Read the Call for Proposals for further information.
Restrictions to Russian Federation or Belarus
The EVN does not currently accept observing projects which include scientists based at institutes in the Russian Federation or Belarus. This restriction will be applied using the affiliations stated on the EVN proposal. This decision was reached collectively by the EVN Consortium Board of Directors following clear national guidelines at some EVN member observatories which prevent such collaboration. The EVN CBD has already agreed earlier that antennas of the Quasar Network in Russia will not participate in EVN observations.
Quasar antennas will not be used in EVN observations until further notice
The recent dramatic events unfolding in Ukraine are in conflict with and challenge the founding spirit of the EVN. Until further notice, data from the Quasar VLBI Network antennas, operated by the Institute of Applied Astronomy in Russia, will not be used in joint observations. Proposals submitted to the EVN PC will, as always, be considered for observation purely based on scientific merit, irrespective of the affiliation or nationality of the researchers. Read the statement from the EVN directors.
A-priori gain calibration update in EVN data
The EVN has extended the compatibility with the CASA data reduction package and the data available in the EVN Data Archive from observations after January 2022 now include the system temperature and antenna gain curve information within the FITS-IDI files. This new feature allows the user to directly run the gain calibration step within the need of leading the ANTAB file and generate a gain curve table. Please, follow the data reduction guide for EVN observations in order to calibrate EVN data with the CASA package, where the necessary steps to run the a-priori gain calibration are detailed.