We present an analysis of the globular cluster (GC) system of the nucleated dwarf elliptical galaxy VCC 1087 in the Virgo Cluster based on Keck LRIS spectroscopy and archival Hubble Space Telescope Advanced Camera for Surveys imaging. We estimate that VCC 1087 hosts a total population of 77+/-19 GCs, which corresponds to a relatively high V-band

The most prominent features on the surface of the solar disc are the sunspots, which have been studied since their detection in the 17th century. Despite this years and centuries of scientific investigations, surprisingly many facets of sunspots are not well understood. In this thesis, the properties of a sunspots' penumbra are derived from the

Recent studies of the substellar population in the Taurus cloud have revealed a deficit of brown dwarfs compared to the Trapezium cluster population. However, these works have concentrated on the highest stellar density regions of the Taurus cloud. We have performed a large scale optical survey of this region, covering a total area of ≃28 deg^2

We surveyed a small sample of metal-rich solar-like stars in our planet search program during the last 3 years. Here we present the detection of a brown dwarf and 3 long-period massive planet (or brown dwarf) candidates as well as one short-period planet candidate with m sin i ˜ 0.1 M_{Jup}. Furthermore, we calculated the upper mass limits of

We describe the serendipitous discovery in the spectroscopic data of the Sloan Digital Sky Survey of a starlike object, SDSS J103913.70+533029.7, at a heliocentric radial velocity of +1012 km s-1. Its proximity in position and velocity to the spiral galaxy NGC 3310 suggests an association with the galaxy. At this distance, SDSS J103913.70+533029.7

We have obtained high-resolution UVES spectra with S/N>100 to accurately characterize the stellar parameters for the transiting planet-hosting star OGLE-TR-10. The obtained values were used to rederive the planetary radius and mean density.