"Using high resolution spectroscopic data obtained with Magellan Inamori Kyocera Echelle (MIKE) at the Magellan telescope at Las Campanas Observatory it was possible to resolve the emission line profiles of [OIII] 5007, Ha and [NII] 6583 in two planetary nebulae belonging to the Local Group galaxy NGC 6822 (Flores-Durán et al. submitted). The two

A 37 year long-term series of monochromatic Aerosol Optical Depth (AOD) has been recovered from solar irradiance measurements performed with the solar spectrometer Mark-I, deployed at Izaña mountain since 1976. The instrument operation is based on the method of resonant scattering, which presents a long-term stability and high precision in

This paper presents the re-construction of the 80 year time series of daily global shortwave downward radiation (SDR) at the subtropical high-mountain Izaña Atmospheric Observatory (IZO, Spain). For this purpose, we combine SDR estimates from sunshine duration (SD) data using the Ångström-Prescott method over the 1933/1991 period, and SDR

Aims: We study the modification of the classical criterion for the linear onset and growth rate of the Rayleigh-Taylor instability (RTI) in a partially ionized (PI) plasma in the one-fluid description by considering a generalized induction equation. Methods: The governing linear equations and appropriate boundary conditions, including gravitational

Rapidly rotating neutron stars are the only candidates for persistent high-frequency gravitational wave emission, for which a targeted search can be performed based on the spin period measured from electromagnetic (e.g., radio and X-ray) observations. The principal factor determining the sensitivity of such searches is the measurement precision of

HST images of some 50 pre planetary nebulae ("pPNe") are now available. A confrontation of images with theoretical shaping models is timely in order to determine whether one of the paradigms emerges as a best fit. The near-nuclear morphologies of twelve HST images of symmetric, bright, and well-resolved pPNe are compared to predictions of four