White dwarf masses can be determined in several ways. Here we compare masses obtained from Balmer line spectroscopy with those derived from trigonometric parallax measurements for an ensemble of cool hydrogen-atmosphere white dwarfs.

We report the first results from a new search for cataclysmic variables (CVs) using a combined X-ray (ROSAT)/infrared (2MASS) target selection that discriminates against background active galactic nuclei. Identification spectra were obtained at the Isaac Newton Telescope for a total of 174 targets, leading to the discovery of 12 new CVs. Initially

“BOOTES-IR" is the extension of the BOOTES experiment, which operates in Southern Spain since 1998, to the near IR (NIR). The goal is to follow up the early stage of the gamma ray burst (GRB) afterglow emission in the NIR, alike BOOTES does already at optical wavelengths. The scientific case that drives the BOOTES-IR performance is the study of

Balloon 090100001 is the brightest (B=11.8) pulsator sdB of the EC14026 class. Moreover, it shows a frequency mode (at 356 s, 2.81 mHz) with one of the hightest amplitude of oscillation (˜ 59 mmag) in its class. At least another frequency is present in a low resolution frequency spectrum. The physical parameters of the star (Teff=29446 K, log g=5

We report the discovery of long period oscillations in the light curve of the bright sdB pulsator Balloon 090100001. We find at least three peaks in the low frequency amplitude spectrum of the star (at periods 2733, 3665, 4378 s) and 10 certain frequencies in the short period range (118-356 s), but probably more than 25 frequencies modulate the

We present Na, Mg and Al abundances in a set of 98 stars with known giant planets, and in a comparison sample of 41 “single” stars. The results show that the [X/H] abundances (with X = Na, Mg and Al) are, on average, higher in stars with giant planets, a result similar to the one found for iron. However, we did not find any strong difference in the