The best-fitting two-dimensional plane within the three-dimensional space of spiral galaxy disc observables (rotational velocity vrot, central disc surface brightness μ0=-2.5logI0 and disc scalelength h) has been constructed. Applying the three-dimensional bisector method of regression analysis to a sample of ~100 spiral galaxy discs that span more

Observations of the optical counterpart to XTE J1650-500 with the Magellan 1 telescope find it fainter than expected based on reports of it's possible detection on the DDS2 red (Groot etal IAUC 7708) and blue (Castro-Tirado etal IAUC 7707) plates. The observations were made with the Sackler MagIC CCD camera in non-photometric conditions on 03 Aug

We analyze high signal-to-noise spectra for 14 globular clusters (GCs) in the Sombrero galaxy, NGC 4594 (=M104), obtained with the LRIS spectrograph on the Keck I telescope. We find generally good agreement between spectroscopic metallicities and previous photometric metallicities based on V-I colors. Further, we use measurements of various Balmer

The IRIS network has been operated continuously since July 1st 1989. To date, it has acquired more than a complete solar cycle of full-disk helioseismic data which has been used to constrain the structure and rotation of the deep solar interior. However, the duty cycle of the network data has never reached initial expectations. To improve this

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We present the first infrared (IR) light curves in the J, H and K bands of δ Lib obtained at different observing runs from 1994 to 1998. These IR light curves, showing a secondary minimum much deeper than in visual bands, have been analysed in order to determine a new set of physical parameters. A new program using the Roche geometry, and stellar