We present optical observations of a ULX in the nearby spiral galaxy IC 342. This variable source has an average X-ray luminosity of some 10^{40} erg/s. At the position of the source there is an ionized nebula (the "Tooth") having huge dimensions (280 x 130 pc), much larger than normal supernova remnants. Our optical spectra reveal highly

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Using extended multicolour CCD photometry of the triple-mode radial pulsator V823 Cas we studied the properties of the coupling frequencies invoked by nonlinear processes. Our results support that a resonance connection affects the mode coupling behaviour. The P1/P0 period ratio of V823 Cas has an “out of range” value if compared with the period

The problem of background independent quantum gravity is the problem of defining a quantum field theory of matter and gravity in the absence of an underlying background geometry. Loop quantum gravity (LQG) is a promising proposal for addressing this difficult task. Despite the steady progress of the field, dynamics remains to a large extend an open

This article is concerned with an extensive study of an infinite-dimensional Lie algebra $mathfrak{sv}$, introduced in the context of non-equilibrium statistical physics, containing as subalgebras both the Lie algebra of invariance of the free Schrodinger equation and the central charge-free Virasoro algebra $Vect(S^1)$. We call $mathfrak{sv}$ the

Context: .The population of known large trans-neptunian objects (TNOs) is growing very fast and the knowledge of their physical properties is a key issue to understand the origin and evolution of the Solar System. Aims: .In this paper we studied the surface composition of the recently discovered TNO 2005 FY9, one of the largest known TNOs (~0.7