En este trabajo se realiza la implementación del método de extinción- distancia para determinar distancias a nebulosas planetarias, utilizando la clasificación espectral que realiza un sistema de redes neuronales artificiales. La aplicación del método mencionado exige la clasificación espectral de un numeroso grupo de estrellas de campo cercanas a

We present the transient nature of INTEGRAL source IGR J17285 2922, identified from a single period of activity during an IBIS/ISGRI Galactic Centre Deep Exposure in September 2003. The source has a maximum detection significance of 14σ in the 20 100 keV energy range and exhibits a flux of 6.5 mCrab before it moves out of the ISGRI field of view

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