The Ca II infrared triplet lines around 8540 Å are good candidates for observing chromospheric magnetism. Model spectra of these lines are obtained by combining a radiation hydrodynamic simulation with a Stokes synthesis code. The simulation shows interesting time-varying behavior of the Stokes V profiles as waves propagate through the formation

We report on a search for gravitational-wave bursts in data from the three LIGO interferometric detectors during their third science run. The search targets sub-second bursts in the frequency range 100-1100 Hz for which no waveform model is assumed and has a sensitivity in terms of the root-sum-square (rss) strain amplitude of hrss ~ 10-20 Hz-1/2

TIMMI2 diffraction-limited mid-infrared images of a multipolar proto-planetary nebula IRAS 16594-4656 and a young [WC] elliptical planetary nebula IRAS 07027-7934 are presented. Their dust shells are for the first time resolved (only marginally in the case of IRAS 07027-7934) by applying the Lucy-Richardson deconvolution algorithm to the data

We present multicolor optical observations of the nearby (z=0.1685) gamma-ray burst GRB 030329 obtained with the same instrumentation over a time period of 6 hours, for a total of an unprecedented 475 quasi-simultaneous BVR observations. The achromatic steepening in the optical, which occurs at t~0.7 days, provides evidence for a dynamic transition

Context: .Protoplanetary nebulae typically present non-spherical envelopes. The origin of such geometry is still controversial. There are indications that it may be carried over from an earlier phase of stellar evolution, such as the AGB phase. But how early in the star's evolution does the non-spherical envelope appear? Aims.Li-rich giants show

In this paper we study the fine structure of the penumbra as inferred from the uncombed model (flux tube embedded in a magnetic surrounding) when applied to penumbral spectropolarimetric data from the neutral iron lines at 6300 Å. The inversion infers very similar radial dependences in the physical quantities (LOS velocity, magnetic field strength