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New beta Cephei and SPB Stars Discovered in Hipparcos Photometry
Molenda-Zakowicz, J.; Polubek, G.
We discuss 34 stars for which we detected new frequencies in Hipparcos Hp magnitudes. 13 of these stars are variables discovered in this paper. For 20 stars, we derive log T_eff and log g from Stromgren or Geneva photometry.
We classify one new beta Cep star, HIP 88352, two new beta Cep suspects, HIP 54753 and 88123, four new SPBs, HIP 1030, …Variable Stars in the Archival HST Data of Globular Clusters M13, M30 and NGC 6712
Pietrukowicz, P.; Kaluzny, J.
We have analyzed archival HST/WFPC2 time-series data of the central parts of globular clusters M13, M30 and NGC 6712 in search for variable objects. Among a total of 21 identified variables there are 15 new discoveries. The sample includes nine RR Lyr stars, two SX Phe stars and seven W UMa-type contact binaries. One object is preliminarily classi…
Kinematical Structure of Wolf-Rayet Winds. II. Internal Velocity Scatter in WN Stars
Niedzielski, A.; Nugis, T.; Skorzynski, W.
The shortward edge of the absorption core velocities - v_black as determined from low resolution archived IUE spectra from the INES database are presented for three P Cyg profiles of NV 1240, HeII 1640 and NIV 1720 for 51 Galactic and 64 LMC Wolf-Rayet stars of the WN subtype. These data, together with v_black of CIV 1550 line presented in Niedzie…
Empirical Absolute Magnitudes, Luminosities and Effective Temperatures of SPB Variables and the Problem of Variability Classification of Monoperiodic Stars
Molenda-Zakowicz, J.; Polubek, G.
We derive semi--empirical log L/Lodot for 27 stars classified as SPB on the basis of Hipparcos photometry and we plot these stars on the log Teff-log L/Lodot diagram. We confirm pulsations of HIP 63210 and HIP 108348 and show that luminosities and masses derived from photometry are of limited use for asteroseismolo…
Searching for Variable Stars in the Central Part of the Globular Cluster M22
Pietrukowicz, P.; Kaluzny, J.
Time-series data taken with the Hubble Space Telescope of three fields covering the central part of the globular cluster M22 have been analyzed in search of variable objects. We report identification of eleven periodic variables of which eight are new discoveries. The sample includes five certain contact binaries as well as one SX Phe star. Two ob…
Interstellar Silicon Abundance
Gnacinski, P.
We present 34 measurements of silicon gas phase column densities in the interstellar medium. We have used spectra containing the SiII 1808 Ang line which were obtained with the Goddard High Resolution Spectrograph (GHRS) aboard the Hubble Space Telescope (HST). Extinction curve parameters are determined for analyzed lines of sight and relation bet…
Kinematical Structure of Wolf-Rayet Winds. I.Terminal Wind Velocity
Niedzielski, A.; Skorzynski, W.
New terminal wind velocities for 164 Wolf-Rayet stars (from the Galaxy and LMC) based on PCyg profiles of lambda1550 CIV resonance line were derived from the archive high and low resolution IUE spectra available form the INES database. The high resolution data on 59 WR stars (39 from the Galaxy and 20 from LMC) were used to calibrate the empirical…
Surface Brightness--Color Relation for Eclipsing Binaries with ubvy Photometry
Semeniuk, Irena
The relation between visual surface brightness and (b-y)_0 color index is constructed for eclipsing binaries with Hipparcos parallaxes and photometry in the Stromgren four-color ubvy system. The relation is consistent with the Popper relation derived for stars with angular diameters obtained mainly from interferometry or from the lunar occultation…
The All Sky Automated Survey. Catalog of about 3800 Variable Stars
Pojmanski, G.
Results of the first two years of observations using the All Sky Automated Survey prototype camera are presented. More than 140000 stars in 50 Selected Fields covering 300 square degrees were monitored each clear night in the I-band resulting in the ASAS Photometric I-band Catalog containing over 5*10^7 individual measurements. Nightly monitoring …
UBVI Color-Magnitude Diagrams in Baade's Window Metallicity Range, Implications for the Red Clump Method, Color "Anomaly" and the Distances to the Galactic Center and the Large Magellanic Cloud
Stanek, K. Z.; Kaluzny, J.; Wysocka, A. +1 more
We analyze the UBVI color-magnitude diagrams towards the Galactic bulge in a relatively low-reddening region of Baade's Window. The dereddened red giant branch is very wide [approx 1.0 mag in (U-B)_0 and approx 0.4 mag in (B-V)_0 and (V-I)_0], indicating a significant dispersion of stellar metallicities, which by comparison with the theoretical is…