The recurrent nova V3890 Sgr-a short review

Recurrent novae eruptions are often observed in most if not all wavelengths from radio to gamma- rays. Here, we present some highlights from observations of the recurrent symbiotic nova V3890 Sagitarii that erupted again the third time in August 2019. Enough material accumulates on the surface of the white dwarf for a thermonuclear eruption to occur after every 29 years. The most recent eruption has been moderately studied over the whole electromagnetic range from GeV gamma-rays by the Fermi/LAT to 1 GHz radio observations with MeerKAT. Most of the different emission types observed from the nova are shock-powered. Observing emission of novae at different wavelengths is useful for determining the ejecta morphology of the nova, dust formation and studying the circumstellar environment around the binary system. High resolution images from the Karl G. Jansky Very Large Array show that the ejecta is not resolved more than a year post-eruption at 5 GHz. However, at 7 GHz, the ejecta show two blobs east-west direction with different brightness. We combine the radio image measurement with optical spectra measurements of velocities to estimate the distance to the nova.