The inclination angle and mass of the black hole in XTE J1118+480

We have obtained optical and infrared photometry of the quiescent soft X-ray transient XTE J1118+480. In addition to optical and J-band variations, we present H- and Ks-band ellipsoidal variations for this system. We model the variations in all bands simultaneously with the WD98 light curve modeling code. The infrared colors of the secondary star in this system are consistent with those of a K7 V, while there is evidence for light from the accretion disk in the optical. Combining the models with the observed spectral energy distribution of the system, the most likely value for the orbital inclination angle is 68 degrees ±2 degrees. This inclination angle corresponds to a primary black hole mass of 8.53+/-0.60 M☉. Based on the derived physical parameters and infrared colors of the system, we determine a distance of 1.72+/-0.10 kpc to XTE J1118+480

Emission Lines of Northern Planetary Nebulae

In this work, we present results of long slit spectrophotometric emission line flux observations of selected planetary nebulae (PNe). We have measured absolute fluxes and equivalent widths (EW) of all observable emission lines. In addition to these observations, electron temperatures (Te), densities (Ne), and chemical abundances were also calculated. The main purpose of this work is to fill the gaps in emission line flux standards for the northern hemisphere. It is expected that the measured fluxes would be used as standard data set for further photometric and spectrometric measurements of HII regions, supernova remnants etc

The inclination angle and mass of the black hole in XTE J1118+480

We have obtained optical and infrared photometry of the quiescent soft X-ray transient XTE J1118+480. In addition to optical and J-band variations, we present H- and K-s-band ellipsoidal variations for this system. We model the variations in all bands simultaneously with the WD98 light curve modeling code. The infrared colors of the secondary star in this system are consistent with those of a K7 V, while there is evidence for light from the accretion disk in the optical. Combining the models with the observed spectral energy distribution of the system, the most likely value for the orbital inclination angle is 68 degrees +/- 2 degrees. This inclination angle corresponds to a primary black hole mass of 8.53 +/- 0.60 M-circle dot. Based on the derived physical parameters and infrared colors of the system, we determine a distance of 1.72 +/- 0.10 kpc to XTE J1118+480

The inclination angle and mass of the black hole in XTE J1118+480

We have obtained optical and infrared photometry of the quiescent soft X-ray transient XTE J1118+480. In addition to optical and J-band variations, we present H- and K-s-band ellipsoidal variations for this system. We model the variations in all bands simultaneously with the WD98 light curve modeling code. The infrared colors of the secondary star in this system are consistent with those of a K7 V, while there is evidence for light from the accretion disk in the optical. Combining the models with the observed spectral energy distribution of the system, the most likely value for the orbital inclination angle is 68 degrees +/- 2 degrees. This inclination angle corresponds to a primary black hole mass of 8.53 +/- 0.60 M-circle dot. Based on the derived physical parameters and infrared colors of the system, we determine a distance of 1.72 +/- 0.10 kpc to XTE J1118+480