The authors present the results of a near-infrared survey of 13 areas containing 16 GGD objects. A total of 12 infrared sources have been detected in five of the surveyed fields; six of them are new detections. An IRAS point source is present in all the areas where the authors have positive detections. The infrared colours J-H, H-K and K-L indicate

A new technique to calculate multilevel non-LTE continuum formation in the UV of stellar winds and plane-parallel, static stellar atmospheres is developed using a local approximate lambda operator similar to those presented by Werner and Husfeld (1985) and Hamann (1986). In the present formulation, the iteration of the transfer equation solution is

The ESO 32-channel infrared (1 -5 micron-meter) grating spectrometer, IRSPEC, was put into operation and made available for Visiting Astronomers in October 1986. In this contribution we describe the reduction scheme implemented in MIDAS to process IRSPEC data taken in any of the two - discrete or Continuous - instrumental modes. The Ins~rument

An attempt is made to explain conflicting experimental data recently obtained concerning the frequency stability of solar oscillations. Extensive data obtained at the Observatorio del Teide are analyzed to determine the lifetimes and frequencies of the l0 and l1 p-modes. The importance of the lifetime of the mode in determining the frequency is

CCD photometry of the M87 jet in the Thuan-Gunn r and g filters is presented. Accurate elliptical models of the underlying stellar emission were subtracted from the reduced and calibrated frames. The residual images show a number of morphological features not clearly seen before such as the faint extension at the end of the jet and faint red

A new phenomenological model for the interpretation of the discrete redshift phenomenon is developed. The model, based on the basic physical notion of adiabatic invariants and quantum conditions, similar to those used in the old quantum theory, leads to the same results as the spinor eigenvalue equation proposed by Cocke. The adiabatic principle