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Optical Outburst of the Halo Black Hole X-ray Transient XTE J1118+480
Optical spectra were obtained of the optical counterpart of the high-latitude (b 62°) soft X-ray transient XTE J1118+480 near its quiescent state (R 18.3) with the new 6.5 m Multiple Mirror Telescope
X-Ray and Optical Variability in NGC 4051 and the Nature of Narrow-Line Seyfert 1 Galaxies
We report on the results of a three-year program of coordinated X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray spectra
Nova Sagittarii 1994 1 (V4332 Sagittarii): The Discovery and Evolution of an Unusual Luminous Red Variable Star
We report photometry and spectroscopy of the evolution of Nova Sagittarii 1994 1 (V4332 Sagittarii) during outburst. We compare the photometric and spectral evolution of this outburst with known
Detection of superhumps in XTE J1118+480 approaching quiescence
We present the results of our monitoring of the halo black hole soft X-ray transient (SXT) XTE J1118+480 during its decline to quiescence. The system has decayed 0.5 mag from 2000 December to its
New Elemental Abundances for V1974 Cygni
We present a new analysis of existing optical and ultraviolet spectra of the ONeMg nova V1974 Cygni 1992. Using these data and the photoionization code Cloudy, we have determined the physical
On the distance, reddening and progenitor of V838 Mon
Extensive optical and infrared photometry as well as low and high resolution spectroscopy are used as inputs in deriving robust estimates of the reddening, distance and nature of the progenitor of
ROSAT observations of the black hole candidate V404 Cygni in quiescence
V404 Cyg was detected with the ROSAT PSPC in a 16 ks observation 1265 days after the 1989 May outburst. This is the first unambiguous detection of a soft X-ray transient or X-ray nova black hole
Periodic Photometric Variability of the Black Hole Binary V404 Cygni
Periodic variations of V404 Cyg having a period of 6.474 +/- 0.005 d with a full amplitude of 0.2 mag were discovered with CCD photometry, in the I band, of the compact star. The light curve consists
GRB 000418: A Hidden Jet Revealed?
We report on optical, near-infrared and centimeter radio observations of GRB000418 which allow us to follow the evolution of the afterglow from 2 to 200 days after the gamma-ray burst. In modeling
New weak-line T Tauri stars in Orion from the ROSAT all-sky survey
We present results of the spectroscopic and photometric follow-up observations of the ROSAT all- sky survey in the direction of the Orion cloud complex. The main goal of these observations is the