Accurate and densely populated BVR C I C lightcurves of supernovae SN 2011fe in M101, SN 2012aw in M95 and SN 2012cg in NGC 4424 are presented and discussed. The SN 2011fe lightcurves span a total range of 342 days, from 17 days pre-to 325 days post-maximum. The observations of both SN 2012aw and SN 2012cg were stopped by solar conjunction, when the objects were still bright. The lightcurve for SN 2012aw covers 92 days, that of SN 2012cg spans 44 days. Time and brightness of maxima are measured, and from the lightcurve shapes and decline rates the absolute magnitudes are obtained, and the derived distances are compared to that of the parent galaxies. The color evolution and the bolometric lightcurves are evaluated in comparison with those of other well observed supernovae, showing no significant deviations.

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 R

We have identified a first group of 33 new candidates for symbiotic stars (SySt) of the accreting-only variety among the 600 255 stars so far observed by the GALAH high-resolution spectroscopic survey of the Southern Hemisphere, more than doubling the number of those previously known. GALAH aims to high latitudes and this offers the possibility to sound the Galaxy for new SySt away from the usual Plane and Bulge hunting regions. In this paper we focus on SySt of the M spectral type, showing an Hα emission with a peak in excess of 0.5 above the adjacent continuum level, and not affected by coherent radial pulsations. These constraints will be relaxed in future studies. The 33 new candidate SySt were subjected to an array of follow-up confirmatory observations (X–ray/UV observations with the Swift satellite, search for optical flickering, presence of a near-UV upturn in ground-based photometric and spectroscopic data, radial velocity changes suggestive of orbital motion, variability of the emission line profiles). According to Gaia eDR3 parallaxes, the candidate new SySt are located at the tip of the Giant Branch, sharing the same distribution in M(KS) of the well established SySt. The accretion luminosities of the candidate new StSt are in the range 1−10 L⊙, corresponding to mass-accretion rates of 0.1-1 10−9 M⊙ yr−1 for WDs of 1 M⊙. The M giant of one of them presents a large Lithium over-abundance.

Context. AX Per is an eclipsing symbiotic binary. During active phases, deep narrow minima are observed in its light curve, and the ionization structure in the binary changes significantly. From ∼2007.5, AX Per entered a new active phase. Aims. We aim to derive the ionization structure in the binary and its changes during the recent active phase. Methods. We used optical high-and low-resolution spectroscopy and UBVR C I C photometry. We modeled the SED in the optical and broad wings of the Hα line profile during the 2007-10 higher level of the AX Per activity. Results. After 10 orbital cycles (∼18.6 years), we again measured the eclipse of the hot component by its giant companion in the light curve. We derived a radius of 27 ± 2 R for the eclipsed object and 115 ± 2 R for the eclipsing cool giant. The new active phase was connected with a significant enhancement of the hot star wind. From quiescence to activity, the mass-loss rate increased from ∼9 × 10 −8 to ∼3 × 10 −6 M yr −1 , respectively. The wind causes the emission of the He ++ zone, located in the vicinity of the hot star, and also is the reason for the fraction of the [O iii] zone at farther distances. Simultaneously, we identified a variable optically thick warm (T eff ∼ 6000 K) source that contributes markedly to the composite spectrum. The source was located at the hot star's equator and has the form of a flared disk, whose outer rim simulates the warm photosphere. Conclusions. The formation of the neutral disk-like zone around the accretor during the active phase was connected with its enhanced wind. It is probable that this connection represents a common origin of the warm pseudophotospheres that are indicated during the active phases of symbiotic stars.

After a quiescence period of about 10 years,the classical EXor source V1118 Ori has undergone an accretion outburst in 2015 September. The maximum brightness (DV 4 mag) was reached in 2015 December and was maintained for several months. Since 2016 September, the source is in a declining phase. Photometry and low/ highresolution spectroscopy were obtained with MODS and LUCI2 at the Large Binocular Telescope, with the facilities at the Asiago 1.22 and 1.82 m telescopes, and with GI-ANO at the Telescopio Nazionale Galileo. The spectra are dominated by emission lines of H I and neutral metallic species. From line and continuum analysis we derive the mass accretion rate and its evolution during the outburst. Considering that extinction may vary between 1.5 and 2.9 mag, we obtainṀ acc = 0.3−2.0 10 −8 M ⊙ yr −1 in quiescence andṀ acc = 0.2−1.9 10 −6 M ⊙ yr −1 at the outburst peak. The Balmer decrement shape has been interpreted by means of line excitation models, finding that from