Photometric and spectroscopic data of the southern contact binary GSC04778-00152 are presented. Six new times of minimum are listed. For modelling purposes, we provide UBVRI phase diagrams of the contact binary with the contribution of the nearby companion removed.

The chromospheric temperature rise to values above the photospheric temperature cannot be due to radiative energy transport alone. We will outline different possibilities for the additional energy transport in the solar atmosphere by processes that require (or exclude) the presence of magnetic fields. We will discuss which of them could be

In this talk, I present the recent data analysis of the COSMOSOMAS experiment. The COSMOSOMAS experiment is placed at the Observatorio del Teide (Tenerife, 2400 m). It observes the sky with 5 channels between 10 and 17 GHz, covering a daily sky region of ca. 7000 squared degrees, with an angular resolution of 1 degree. Its aim is the study of CMB

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

Following the report of a new outburst of the accreting millisecond pulsar SAX J1808.4-3658 by Markwardt and Swank (ATel #1728), the source was observed using the CTIO/SMARTS 1.3m telescope on MJD 54732.0998, in I- and H- bands. We clearly detected the source at magnitudes significantly higher than its quiescent level, confirming that the source is

We present the results of the first multiwavelength observing campaign on the high-mass X-ray binary LS I +61 303, comprising observations at the TeV regime with the MAGIC telescope, along with X-ray observations with Chandra, and radio interferometric observations with the MERLIN, EVN, and VLBA arrays, in 2006 October and November. From our MERLIN