Three-dimensional structure of a sunspot light bridge
Context. Active regions are the most prominent manifestations of solar magnetic fields; their generation and dissipation are fundamental problems in solar...
Through thick and thin: Structure of the Galactic thick disc from extragalactic surveys
Context. We aim to understand the accretion history of the Milky Way by exploring the vertical and radial properties of the Galactic thick disc. Aims: We study...
Time series of high resolution photospheric spectra in a quiet region of the Sun. II. Analysis of the variation of physical quantities of granular structures
From the inversion of a time series of high resolution slit spectrograms obtained from the quiet sun, the spatial and temporal distribution of the...
Time series of high resolution photospheric spectra in a quiet region of the sun. I. Analysis of global and spatial variations of line parameters
A 50 min time series of one-dimensional slit-spectrograms, taken in quiet sun at disk centre, observed at the German Vacuum Tower Telescope (Observatorio del...
Time variation of the fine structure constant in the early universe and the Bekenstein model
Aims:We calculate the bounds on the variation in the fine structure constant at the time of primordial nucleosynthesis and at the time of neutral hydrogen...
Time-correlation of the solar p-mode velocity signal from GOLF
Since the launch of SOHO, the Solar Heliospheric Orbital Observatory, the helioseismic observations are nearly uninterrupted. The GOLF instrument (A. Gabriel et...
Time-dependent modelling of short-term variability in the TeV-blazar VER J0521+211 during the major flare in 2020
The BL Lacertae object VER J0521+211 underwent a notable flaring episode in February 2020. A short-term monitoring campaign, led by the MAGIC (Major Atmospheric...
Time-resolved photometry and spectroscopy of the new deeply-eclipsing SW Sextantis star HS 0728+6738
We present time-resolved optical spectroscopy and photometry, and far-ultraviolet spectroscopy of HS 0728+6738, a cataclysmic variable discovered in the Hamburg...
Time-resolved photometry of the nova remnants DM Gem, CP Lac, GI Mon, V400 Per, CT Ser and XX Tau
We present the first results of a photometric survey of poorly studied nova remnants in the Northern Hemisphere. The main results are as follows: DM Gem shows a...