V959 Mon (Nova Mon 2012) was first detected by the Fermi Large Area Telescope in June 2012, as a transient gamma-ray source. Subsequent optical observations showed that this gamma-ray emission was due to a classical nova explosion. Multi-frequency observations of V959 Mon with the VLA between June and September 2012 revealed dramatic brightening, and a spectrum that steepened with increasing frequency. High resolution radio images of V959 Mon using e-MERLIN are presented here, at six epochs between September 2012 and February 2014 which show morphological evolution of the source. While early e-MERLIN observations of V959 Mon show an east-west elongation in the ejecta morphology, subsequent observations suggest that the ejecta become elongated in the north-south direction. Our high-resolution observations of this surprising evolution in the structure of V959 Mon can assist us in further understanding the behaviour and morphology of nova ejecta.

VLBA polarization observations of the 135 AGNs in the MOJAVE-I sample have recently been obtained at four frequencies between 1.3 and 1.7 GHz. These observations are sensitive to compact radio emission on scales from a few to tens of parsecs from the VLBA core. VLBA observations at the same frequencies were obtained earlier for 34 BL Lac objects, enabling a multiepoch study of the extended radio jets of these objects. As an initial step in this study, we have constructed new images for three BL Lac objects with rich jet structures: 0735+178, 1803+784 and 2200+420 (BL Lac), which are analyzed together with the previous results of Hallahan and Gabuzda (2008). We consider the morphology, polarization (magnetic field) structure and Faraday rotation distributions of these objects.11th European VLBI Network Symposium Users Meeting,

ACKNOWLEDGMENTSe-MERLIN is a National Facility operated by the University of Manchester at Jodrell Bank Observatory on behalf of STFC.

No abstract