Using Advanced Camera for Surveys-Hubble Space Telescope images to yield continuum-subtracted photometric maps in Hα of the Sbc galaxy M51 and the dwarf irregular galaxy NGC 4449, we produced extensive (over 2000 regions for M51 and over 200 regions for NGC 4449) catalogs of parameters of their H II regions: their Hα luminosities, equivalent radii

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The planetary nebula TS 01 (also called PN G 135.9+55.9 or SBS 1150+599A) with its record-holding low oxygen abundance and its double degenerate close binary core (period 3.9 h) is an exceptional object located in the Galactic halo. We have secured observational data in a complete wavelength range to pin down the abundances of half a dozen elements

Context. Recent accurate abundance analyses of B-type main sequence stars in the solar vicinity has shown that abundances derived from these stellar objects are more homogeneous and metal-rich than previously thought. Aims: We investigate whether the inhomogeneity of abundances previously found in B-type stars in the Ori OB1 association is real

We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic Globular Clusters to construct global present-day mass functions for 17 globular clusters utilizing multi-mass King models to extrapolate from our observations to the global cluster behavior. The global present-day mass functions for these clusters are

Spectral data are presented for comets 2006 VZ13 (LINEAR), 2006 K4 (NEAT), 2006 OF2 (Broughton), 2P/Encke and 93P/Lovas I, obtained with the Cerro Tololo Inter-American Observatory 1.5-m telescope in 2007 August. Comet 2006 VZ13 is a new Oort cloud comet and shows strong lines of CN (3880 Å), the Swan band sequence for C2 (4740, 5160 and 5630 Å)