Using a numerical three-dimensional MHD modelling of magneto-acoustic wave propagation in a realistic magnetostatic sunspot model we investigate the influence of the magnetic field on the parameters measured by local helioseismology. We find that the variations of temperature as well as the presence of the magnetic field cause important changes to

Blue compact dwarf (BCD) galaxies are metal-poor systems going through a major starburst that cannot last for long. We have identified galaxies which may be BCDs during quiescence (QBCD), i.e., before the characteristic starburst sets in or when it has faded away. These QBCD galaxies are assumed to be like the BCD host galaxies. The SDSS DR6

There is no agreement on the thermal structure of the solar chromosphere. While results of the CO observations and 3D MHD simulations suggest very cool structures in the upper atmosphere, SUMER observations of UV spectral lines is interpreted as signature of a full-time hot chromosphere. We tried to look for cool structures in the solar

We report a re-brightening of the millisecond X-ray pulsar IGR J00291+5934. In August the source performed an outburst which was detected in X-ray, UV and optical (ATel #1660, #1664, #1665, #1666, #1667, #1668). Since then we have continued to monitor this source with the Faulkes Telescope North in many optical filters as it appeared to be fading

We have observed the accreting millisecond X-ray pulsar SAX J1808.4-3658 in its current outburst (ATel #1728, #1732, #1733) in the radio band with the Australia Telecope Compact Array (ATCA) on 2008 September 26th for about 5h (03:39 - 08:35 UT). The radio-counterpart was not detected. The 3-sigma upper-limits are 0.45 mJy/beam at 4.8 GHz and 0.72

Context: Hydrodynamical cosmological simulations predict flows of the intergalactic medium along the radial vector of the voids, approximately in the direction of the infall of matter at the early stages of the galaxy formation. Aims: These flows might be detected by analysing the dependence of the warp amplitude on the inclination of the galaxies