We present results of nonlinear, two-dimensional, numerical simulations of magneto-acoustic wave propagation in the photosphere and chromosphere of small-scale flux tubes with internal structure. Waves with realistic periods of three to five minutes are studied, after horizontal and vertical oscillatory perturbations are applied to the equilibrium

The nonlinear development of the kink instability in a horizontal magnetic flux tube with a field strength exceeding the equipartition value lying initially in the deep convective zone is calculated. A Lagrangian numerical code is developed to obtain solutions for the system of equations dictating the evolution of a thin magnetic flux tube in a

IAUC 4257 available at Central Bureau for Astronomical Telegrams. IAUC 4257 available at Central Bureau for Astronomical Telegrams.

When I was assigned the time in La Palma on the JKT, I gave thanks for my extraordinary luck that the observations were scheduled exactly at the perihelion of Comet LINEAR, or C/1999 S4 (LINEAR) as it is correctly known. This would be able to get data on the comet at the start of each night without interrupting the main programme. At the time I

We present Gran Telescopio CANARIAS CanariCam 8.7 μm imaging and 7.5-13 μm spectroscopy of six local systems known to host an active galactic nucleus (AGN) and have nuclear star formation. Our main goal is to investigate whether the molecules responsible for the 11.3 μm polycyclic aromatic hydrocarbon (PAH) feature are destroyed in the close

We present visible and near-IR spectra of the nucleus of comet 162P/Siding Spring (also known as 2004 TU12) obtained in 2004 December, while it had no detectable coma. This is the third object observed to have intermittent cometary activity even when relatively close to the Sun. The spectra show no strong features in this wavelength range. This