We present lithium observations of 23 X-ray selected candidate members of alpha Per, which are part of a larger sample of stars identified through two ROSAT surveys of the cluster. Our observations on one hand allowed us to confirm membership for 18 of the candidates, thus suggesting that a high percentage of the whole X-ray selected candidates are

Twenty magnetic Chemically Peculiar (CP2) stars of the SrCrEu subgroup mostly brighter than the 7.5 visual magnitude have been investigated in the near infrared at 1.25, 1.6 and 2.2 mu . The stars HD 3980, HD 24712, HD 49976, HD 83368, HD 96616, HD 98088, HD 118022, HD 125248, HD 148898, HD 203006, and HD 220825 have been found to be variable in

We present new near-infrared images and spectra of the circumnuclear star formation regions in M100. Images in J, H, and K have been obtained in conditions of 0.3'' seeing using IRCAM3 on UKIRT, and show a host of objects not apparent in previous images (cf. Knapen et al. 1995, ApJ, 443, L73). We have also obtained H- and K-band spectra with CGS4

El conocimiento de la distribución y evolución de los campos de velocidades a gran escala en la zona de convección solar es una de las claves para la comprensión tanto de los mecanismos de transporte energético, que en esta zona son principalmente convectivos, como de los fenómenos magnéticos allí presentes: actividad, dinamo solar, etc. En este

La tesis presenta los resultados del experimento Bartol-IAC sobre medidas de la anisotropía en el Fondo Cósmico de Microondas. Estas observaciones se realizaron en los meses de Junio y Julio de 1994 en el Observatorio del Teide. Se observó la región del cielo a delta=+40 grados en cuatro bandas a lamda=3,3; 2,1; 1,3 y 1,1 mm. En la tesis e han

Three different types of evidence are presented in favour of the hypothesis that the HII regions in disk galaxies with H-alpha luminosities greater than a critical value of 10^(38.6)^ erg s^(-1)^ are density bounded, and that the escaping Lyman continuum photons from these are the principal ionizing agents for the diffuse ISM in disk galaxies. This