Unexpected Early Periastron Passage and Eclipse in the Symbiotic System R AQR

We propose ToO/DDT HST WFC3 observation of the R Aqr symbiotic system to obtain high S/N multiwavelength - UV to Optical - images of the binary environment and of the ejecta resulting from the recent - earlier then expected - periastron passage of the WD accretor. This observation is critical for studying this phenomenon (observable only about twice a century, with the next periastron passage expected in about 40 years). The effects of the periastron passage will include enhanced accretion and mass ejections and very likely new jet formation.