We present results from a two year intensive monitoring of BL Lac object 3C 66A (PKS 0219+428). This object was observed in outburst during these two years. It reached the brightest ever observed magnitude on V=13.59 (1.2.1995) and on K=10.59 (15.2.1994). The optical and infrared light curves are characterised by randomly distributed fast flares

We have obtained spectra with the 10-m Keck telescope of a sample of 24 galaxies having colors consistent with star-forming galaxies at redshifts 2 ≲ z ≲ 4.5 in the Hubble Deep Field (HDF). Eleven of these galaxies are confirmed to be at high redshift (zmed=3.0). The spectra of the confirmed high-redshift galaxies show a diversity of features

Recently, models for Advection Dominated Accretion Flow (ADAF) have been shown to explain many of the quiescent properties of the X-ray and optical emission from black hole soft X-ray transients (BH SXT) (Narayan, McClintock and Yi 1996 ApJ 457, 821; Narayan, Barret and McClintock 1996, submitted to ApJ). One novel feature of the ADAF model is that

We present echelle spectroscopy in the 3550 to 7010 A range for two positions of the Orion Nebula. The data were obtained with the 2.1-m telescope at Observatorio Astronomico Nacional in San Pedro Martir, Baja California. We have measured the intensities of several permitted lines of C(+) , N(+) , N(++) , O(0) , O(+) , Ne(0) , Si(+) , Si(++) which

We present Keck spectroscopy of small (r 2 objects. The majority of the emission-line systems have properties similar to local Hii galaxies.

We have acquired CO J=1->0 mapping of a region 2x2arcmin^2^ about the cometary nebula and jet outflow source 1548c27. We find little evidence for interaction between the jet and molecular cloud, although it is found that the reflection nebula is embedded within a neutral condensation of size =~10^2^arcsec. Kinematic variations across the source