The 1.5m solar telescope GREGOR is being constructed at Tenerife, Spain. Its purpose is to observe with high spatial and spectral resolution small-scale dynamic magnetic features on the Sun. The telescope is completely open with retractable dome and actively cooled primary mirror made of silicon carbide to minimize thermal effects on the image

Interpretation of linearly polarized parameters of the spectral lines of the second solar spectrum permits to obtain information about the magnetic field vector of the medium where the spectral lines are formed, provided suitable theoretical and numerical methods be applied to extract the physical information. This linear polarization is modified

To study the small-scale dynamic processes of magneto-convection in the solar photosphere in more detail than currently achieveable, not only the spatial resolution has to be increased, but also the information content of observations. In order to do so, several wavelengths and spectral lines must be observed simultaneously. This is often achieved

Class II methanol Masers and ultracompact HII regions (UCHII) trace regions of massive star formation. We have carried out mid-IR imaging of a selected number of star forming complexes traced by UCHII and methanol maser emission to determine their large scale properties. The mid-IR images from 8 to 20 micron were obtained with the mid-IR camera CID

Bright points (BPs) visible in the G band at 430 nm are commonly used as tracers of magnetic fields, indicating the location of kG flux concentrations. To study the actual magnetic properties of G-band BPs, we took observations in 2003 and 2005, employing simultaneously a speckle setup in the G band and vector spectropolarimetry to derive the

The magnetic sensitivity of the solar spectrum is caused by the Zeeman effect and by a variety of less familiar physical mechanisms by means of which a magnetic field can create and destroy spectral line polarization. This paper highlights how plasma diagnostic tools based on them could help us to explore the magnetism of the quiet regions of the