A study of [Fe Ii] lines at various positions within the H Ii regions M42 and M43 is presented. The relative intensities of selected optical [Fe Ii] lines are shown to be correlated with the intensity of the apparent nebular continuous spectrum. Since the continuum of H Ii regions is known to be mostly stellar radiation scattered by dust intermixed

Highly collimated bipolar outflows have been detected in the planetary nebula NGC 6572 via ground-based optical imagery and high-resolution long-slit spectroscopy. Kinematics and morphology together provide strong evidence of a direct interaction between the collimated outflows and the nebular elliptical shell, creating a double point-symmetric

Regular monitoring of the light curves of blazars has become increasingly valuable as space missions such as ROSAT, CGRO and ASCA have subjected many objects to detailed multi-wavelength monitoring. Over recent years collaborations such as the OJ-94 collaboration have benefitted greatly from the input of amateur astronomers observing both visually

We present a CCD-based photometric survey covering 870 arcmin^2 in a young stellar cluster around the young multiple star sigma Orionis. Our survey-limiting R, I, and Z magnitudes are 23.2, 21.8, and 21.0, respectively, the completeness being about 2.2 mag brighter. From our color-magnitude diagrams, we have selected 49 faint objects (I=15-21 mag)

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We propose and experimentally realize an algorithmic benchmark that demonstrates coherent control with a sequence of quantum operations that first generates and then decodes the cat state (|000...>+|111...>)/sqrt(2) to the standard initial state |000...>. This is the first high fidelity experimental quantum algorithm on the currently largest