Planetary nebula NGC6543 has a complex structure with a central hot bubble showing both point- and plane symmetry, and a large outer halo that is likely interacting with the local ISM. Between these two structures the HST has revealed a series of a least nine regularly spaced concentric circular rings that are faint and have low contrast. The

Vulcanism was first detected on Io in 1978 by Voyager 1. Since then it has been recognised that Io is the most volcanically active body in the Solar System. Although the initial volcanic activity observed was in the form of SO[2] geysers and sulphur lakes, the Galileo mission has detected temperatures as high as 1800K on the surface, far in excess

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Using a sample of 654 objects selected from the Sloan Digital Sky Survey (SEGUE) plates, we evaluated and adjusted the SDSS target algorithm for Blue Horizontal Branch (BHB) stars. We then tested the spectroscopically determined surface gravity for these stars against the Lenz et al. 1998 photometric ``v-parameter" = 0.283(u-g) - 0.354(g-r) + 0.455

Distant clusters of galaxies provide a powerful method to study the formation and evolution of galaxies, and large scale structure of the Universe. However, the number of known clusters at high redshift (z > 0.5) is still very reduced. As a preparatory work for detailed studies with GTC, we are searching for high redshift clusters in public wide

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