Meeting ANS Collaboration 29-30 Sept 2012

posted: 6th October 2012

In 2012 the annual meeting of ANS Collaboration (directed by prof. U. Munari) was held at the observatory of Campo dei Fiori. Unfortunately the weather was not fine and no observations were possibile during the meeting. Many partecipants presented their work within the collaboration both in multiband photometry and spectroscopy. A list of the arguments can be found in the pages devoted to the meeting and covered large field photometry, 15:50 narrowband photometry (Stromgren) - (O[III], Ha) , RAVE/APASS photometry, observations of R Aqr, CI_Cyg eclipse, 9:40 A DT Ser, spectroscopic survey of Red Clump stars, spectroscopic orbits of bright symbiotic stars, IPHAS 205836.43+503307.2 light curve, calibration of photometric sequences, comments and developments on ANSphotometry software .

Spectroscopic confirmation of two FU Orionis stars in NGC 7000 / IC 5070

posted: 30th August 2010

Brightening of several magnitudes of two very young stars (FU Orionis variables) has been confirmed spectroscopically with our 60 cm telescope within ANS Collaboration (directed by prof. U. Munari). Our observations (by A. milani and P. Valisa) are published on ATEL 2808 and CBET 2428 .
Both stars belong to the star forming region around popular nebula NGC 7000 (North America). The star reported on ATEL 2801 was discoverder by E. Semkov, S. Peneva (Institute of Astronomy, Sofia, Bulgaria) and is already known as an infrared source and emission line star named HBC722. Second star discovery by K. Itagaki, Yamagata, Japan is reported on CBET 2426.
Both stars show spectral signature tipical of FU Ori objects with strong absorption of Mg I, Na I, (Ba II, Li I for HBC 722) as well as weak emission from H_alpha with P Cyg profile.

Paper on outburst of the Very Fast Nova Aql 2009 (V1722 Aql)

posted: 4th August 2010

Nova Aql 2009 (V1722 Aql) was discovered by Nishiyama & Kabashima (2009) on 2009 December 14.40 UT. Our observatory started spectroscopic follow-up within ANS Collaboration (directed by prof. U. Munari). Five spectra at low resolution were recorded and absolutely fluxed up to Jan 15th 2010. A high resolution echelle spectrum was also recorded and showed Doppler broadening of emission lines that permitted the measure of the expansion velocity of the ejecta. From the strenght of diffuse interstellar bands we obtained also an estimation of the reddening and thus the distance of this nova.
More info on this topic are reported in the paper pages.

Discovery of Coronal Emissions from Nova V407 Cyg

posted: 12th April 2010

High resolution echelle spectra of V407 Cyg recorded by Paolo Valisa with 0.6 m telescope of Schiaparelli Observatory in the period end March-early April within ANS Collaboration (directed by U. Munari) showed the presence of coronal lines. These emission lines are produced by Fe, Ar, Ni, Si in such a high ionisation state that atoms had lost lot of electrons, perhaps 10 or 15. This is evidence of high energy ionisation source involving X rays. Our observations have been pubblished in Astronomers Telegram (ATEL) 2546

Outburst of Symbiotic Nova V407 Cyg

posted: 13th March 2010

On March 10, 2010, Japanese observers K. Nishiyama and F. Kabashima discovered V407 Cyg in outburst with V=7.4, far brighter than ever recorded for this star. In our observatory, within ANS Collaboration we obtained echelle and low resolution spectroscopy (CBET 2204) that showed clear signs of a classical nova outburst superimposed upon the spectrum of a symbiotic (Mira) star. It is now suspected that the white dwarf in the V407 Cyg system has undergone a classical nova outburst. The ejected shell could impact with the Mira wind creating shock fronts with emission of radio and X rays. A detailed spectroscopic follow-up of V407 is on going in Asiago and our observatory.

Outburst of Symbiotic star V1413 Aql (AS338)

posted: 13th March 2010

The Symbiotic star V1413 Aql entered a new outbursting phase at beginning of March 2010 rising from V=13 to V=10.9. Our observatory started a spectroscopic follow-up within ANS Collaboration (directed by prof. U. Munari). An eclipse of the outbursting white dwarf and accreting disc will occour around mid May (see CBET 2202) thus offering the possibility of spectroscopic mapping.