Light curves of the very low-mass member of the alpha Persei open cluster, AP J0323+4853, obtained during two different observing runs in 1994 and 1995, display a starspot rotational modulation of period ~7.6h. With a most likely mass of 0.09 Msolar, close to the substellar limit, AP J0323+4853 is the lowest mass star so far for which a photometric

The symbiotic nova RR Telescopii has been observed with the 1.5 m telescope of the Cerro Tololo Inter-American Observatory (CTIO), using the 1.5 m bench-mounted echelle spectrograph in conjunction with a Tektronix CCD. It displays a rich emission-line spectrum, ranging in excitation from O I to [Ni VIII]. We present a list of 491 measured lines

We report intermediate resolution H alpha spectroscopy of the black hole candidate Nova Muscae 1991 during quiescence. We classify the companion star as a K3-K4V which contributes 85 plusmn 6 percent to the total flux from the binary. The photospheric absorption lines are broadened by 106 plusmn 13 km s^-1 with respect to template field stars

Not Available

This paper discusses the Galactic plane as a case history of the application of different kinds of data bases to the problem of the large-scale Galactic structure. The shape of the Galaxy, and tilts and warps in the Galactic plane are examined.

Segments alignment is one of the fundamental factors affecting the shape of the PSF of a segmented mirror telescope. Tilt and piston of each segment must be very well and uniformly adjusted in relation with the rest of the segments. The Hartmann-Shack sensor is very efficient in detecting the local wavefront tilt, but the task to take measurements