In search for deviations from homologous expansion in planetary nebulae we present a 3D morphokinematical model of NGC 7009. The model has been constructed with Shape based on PV diagrams from the literature and HST images. ...

Results of CCD photometry using V and R filters are reported for 33 RR Lyrae stars in M15. The periodicities of some variables have been revised and new ephemerides are given. The Blazhko effect, previously reported in ...

The notion that comets supplied the primitive Earth with the requisite chemical species for the process of chemical evolution, which is widely held to have led to the origin of life on Earth, has now gained considerable ...

CMEs have been observed for over 30 years with a wide variety of instruments. It is now possible to derive detailed and quantitative information on CME morphology, velocity, acceleration and mass. Flares associated with ...

A reanalysis of the radio continuum emission from circumnuclear regions of the barred galaxies NGC 1022, NGC 1326, and NGC 4314 is presented. The spatial distributions of Ha and radio continuum are similar and suggest the ...

We derive a new class of exact solutions of Einstein's equations providing a physically plausible hydrodynamical description of cosmological matter in the radiative era, between nucleosynthesis and decoupling. The solutions ...

Context. Short-period high-amplitude pulsating stars of Population I (delta Sct stars) and II (SX Phe variables) exist in the lower part of the classical (Cepheid) instability strip. Most of them have very simple pulsational ...

It has been suggested that in the interplanetary medium Alfven waves may be significantly amplified or damped during large solar proton events. This implies the increase or decrease of the ambient magnetic fluctuations in ...