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ANS Collaboration is a growing Italian network of small and medium size telescopes performing spectroscopy (low and medium resolution single dispersion, and Echelle high resolution modes) and UBV RCIC CCD photometry of symbiotic stars and novae mainly, but with interest also on other types of objects like optical transients, eclipsing binaries, X-ray source counterparts and on-call follow-up observations of selected targets from some surveys like IPHAS or RAVE. In the present form ANS started operations in 2005, and at the time of writing has logged on symbiotic stars 14602 photometric runs and a rich ensemble of low and high resolution, absolutely fluxed spectra. the paper describes the internal organization, operation modes and procedures, and presents sample data and performance statistics.

We present optical spectroscopy collected at seven epochs and BVRCIC photometry obtained at 1227 epochs of nova V723 Cas, covering the time interval between 2007 and 2015. The mean magnitude during this period, stable at ~3 mag brighter than in quiescence, and the continuous presence of strong [Fe X] and other high-ionization emission lines, indicates that the nuclear burning at the surface of the white dwarf is continuing 20 years past the initial outburst. The light curve shows a large amplitude (2 mag) orbital modulation, which is governed by the visibility of the irradiated side of the secondary star. Our observations do not confirm the reported increase with time of the orbital period of V723 Cas, a period of P=16.638 383 ± 0.000 025 h satisfying equally well all available observations in all bands. Our observations also do not confirm the presence of an additional periodicity around P=15.2397 h from which V723 Cas was classified as an intermediate-polar system. [ABSTRACT FROM AUTHOR]

After recent improvements to the Pavia model of two-nucleon knockout from 16O with electromagnetic probes the calculated cross-sections are compared to experimental data from such reactions. Comparison with data from a measurement of the 16O (e,e’ pn) reaction cross-section shows much better agreement between the experimental data and the results of the theoretical model than was previously observed. In a comparison with recent data from a measurement of the 16O ( $ \gamma$ ,pn) reaction cross-section the model over-predicts the measured cross-section at low missing momentum. [ABSTRACT FROM AUTHOR]