Transiting planet systems offer a unique opportunity to observationally constrain proposed models of the interiors (radius, composition) and atmospheres...
Blue Massive Stars in NGC 55: A First Quantitative Study
We present the first census of blue massive stars in NGC 55, a galaxy of the Sculptor group at 1.94 Mpc. This study is based on optical low-resolution spectra...
Blue straggler stars in the unusual globular cluster NGC 6388.
We have used multi-band high resolution HST WFPC2 and ACS observations combined with wide field ground-based observations to study the blue straggler star (BSS)...
Blue stragglers in open clusters - A test of the binary hypothesis
A search for binaries among 17 blue stragglers in five galactic clusters, NGC 7789, 6633, 6819, 6939, and M 67, has been performed using measurements of radial...
The integrated Balmer lines of unresolved stellar systems have been widely used as age indicators, since they are sensitive to the temperature of the main...