A ring-diagram analysis of solar oscillations has been applied to a 3 day time series of full-disk Doppler images obtained at Mount Wilson. A model of the three-dimensional power spectrum assuming a Lorentzian profile in frequency and the advection of the wave front by horizontal flows has been fitted to the observed spectrum. The model provides

We report on the x-ray spectrum and lightcurve of the eclipsing Low-Mass X-ray Binary (LMXB) 4U2129+47 as observed with the ROSAT PSPC during its current quiescent state. Contrary to earlier indications with the ROSAT HRI, the eclipse seen during the high state is still present. The eclipse duration, amplitude, and the fraction of residual flux

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We present the first results on the optical identification of 89 sources with S(0.5-2 keV)>=1.7x10^-14 erg s^-1 cm^-2 detected in eight ROSAT Position Sensitive Proportional Counter (PSPC) observations targeted on the second Lockman hole region. Because of the low Galactic HI column density towards this field [N_HI~(6-12)x10^19 cm^-2] the X-ray

We present high and low resolution spectroscopy and narrow-band imaging of the unusual bipolar outflow source NGC 6537. As a consequence, we are able for the first time to construct large scale velocity maps of this source; note the presence of strongly variable core outflow densities, rising to a peak value n_e_~1.7x10^4^cm^-3^; find evidence for

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