Romano L. M. Corradi

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Some classes of stars, including novae and supernovae, undergo explosive outbursts that eject stellar material into space. In 2002, the previously unknown variable star V838 Monocerotis brightened suddenly by a factor of approximately 10(4). Unlike a supernova or nova, it did not explosively eject its outer layers; rather, it simply expanded to become a(More)
V838 Mon is marking one of the most mysterious stellar outbursts on record. The spectral energy distribution of the progenitor resembles an under-luminous F main sequence star (at V =15.6 mag), that erupted into a cool supergiant following a complex and multi-maxima lightcurve (peaking at V =6.7 mag). The outburst spectrum show BaII, LiI and lines of(More)
We present spectroscopic and photometric observations of the recent peculiar outburst of V838 Mon, carried out at Rozhen and Toru´n observatories. Our data cover a period of three months beginning just before the second eruption. The evolution of the outburst is divided into four phases. The changes of particular spectral features for each of these phases(More)
One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two extremes of phase corruption by the atmosphere. While in radio it is possible to obtain calibrated phases for the science(More)
We are developing a project aimed at studying the physical properties, origin and evolution of low-ionization structures in planetary nebulae. Within this project we have identified a number of pairs of highly collimated low-ionization jet-like features (Gonçalves et al. 2001). In spite of being very similar to real jets, they have the intriguing property(More)
Classically, optical and near-infrared interferometry have relied on closure phase techniques to produce images. Such techniques allow us to achieve modest dynamic ranges. In order to test the feasibility of next generation optical interferometers in the context of the VLTI-spectro-imager (VSI), we have embarked on a study of image reconstruction and(More)
GHαFaS a new Fabry-Perot system, is now available at the William Herschel Telescope. It was mounted, for the first time, at the Nasmyth focus of the 4.2 meter WHT on La Palma in July 2007. Using modern technology, with a spectral resolution of the order R∼15000 , and with a seeing limited spatial resolution, GHαFaS will provide a new look at the Hα-emitting(More)
We have measured angular dimensions of 312 planetary nebulae from their images obtained in Hα (or Hα + [NII]). We have applied three methods of measurements: direct measurements at the 10% level of the peak surface brightness , Gaussian deconvolution and second-moment deconvolution. The results from the three methods are compared and analysed. We propose a(More)
The planetary nebula stage is the ultimate fate of stars with masses one to eight times that of the Sun (M(⊙)). The origin of their complex morphologies is poorly understood, although several mechanisms involving binary interaction have been proposed. In close binary systems, the orbital separation is short enough for the primary star to overfill its Roche(More)