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GPM1 - a catalog of absolute proper motions of stars with respect to galaxies
Rybka, S. P.; Yatsenko, A. I.
The description of the first version of the General Compiled Catalogue of Absolute Proper Motions (GPM1) for a sample of HIPPARCOS stars, derived with respect to galaxies within the plan called Catalogue of Faint Stars (KSZ, Deutch 1952), is presented. The principal aim of the GPM1 construction was to provide absolute proper motions of stars to de…
Analysis of Optical and Ultraviolet Spectroscopy of the DAZ White Dwarf G74-7
Bergeron, P.; Wesemael, F.; Billères, M. +1 more
We present new spectroscopic and photometric observations of the cool DAZ white dwarf G74-7. These data are combined with archival HST Faint Object Spectrograph data covering the range 1700-3200 Å, allowing estimates of the Ca, Mg, and Fe abundances in this object. Our analysis suggests that G74-7 is a hydrogen-rich star of normal gravity, with T<…
Comments on the amplification bias in lens statistics
Hamana, Takashi; Futamase, Toshifumi; Futamase, Kayoko +1 more
Amplification bias selection effects play an important role in lens statistics. We carefully examine the effect of amplification bias on lens statistics taking the following points into account. First, because each lens model has its own amplification bias, it must be estimated self-consistently. Secondly, in general, because the bias depends not …
Systematic Errors in the FK5 Catalog as Derived from CCD Observations in the Extragalactic Reference Frame.
Stone, Ronald C.
This paper presents new positions for 689 FK5 stars determined directly in the extragalactic reference system from CCD scan observations made with the Flagstaff Astrometric Scanning Transit Telescope (FASTT). All the observations were made in 1994-1996 with an accuracy of ∼±40 mas in each coordinate. When these positions are compared with their co…
HST-FGS parallaxes of two high-velocity stars.
MacConnell, D. Jack; Osborn, Wayne H.; Miller, Richard J.
Astrometric position measurements with the Hubble Space Telescope's Fine Guidance System have been used to measure the trigonometric parallaxes of two high-velocity stars, R50 = G166-37 and W624 = G16-25. In both cases, the parallaxes are small and confirm large velocities in the galactocentric rest frame. We derive pi_ {abs} = 5.2 +/- 0.7 mas and…
The Supergiant Binary BM CAS
Evans, N. R.; Fernie, J. D.
Attracted by an earlier claim (Thiessen 1956) that BM Cas is an eclipsing binary with one component a classical Cepheid, we have obtained new photometry and IUE ultraviolet spectra of the system. While we verify that there is variability in addition to the eclipses, we conclude that there is no classical Cepheid present. The variability is irregul…
A Transition Disk Model Fit for the Broadband X-Ray Spectrum of Cygnus X-1
Rao, A. R.; Misra, R.; Melia, F. +1 more
The broadband (2-500 keV) data for Cygnus X-1 from observations by EXOSAT, OSSE, and the XMPC balloon, have been fitted to the transition disk model. In this model the emission is from the inner region of an accretion disk where the temperature is a rapidly varying function of radius and the radiative mechanism is saturated Comptonization. We fit …
Far-Ultraviolet Imaging of the Large Magellanic Cloud Populous Cluster NGC 1978 with WFPC2
Casertano, Stefano; Cole, Andrew A.; Ballester, Gilda E. +13 more
We have imaged the ∼2.2 billion-year-old Large Magellanic Cloud populous cluster NGC 1978 in the far-ultraviolet and visible with the second Wide Field/Planetary Camera (WFPC2) on the Hubble Space Telescope. The far-ultraviolet images show a sparse stellar field with little apparent density enhancement in the cluster core. The visible images are d…
Far-Ultraviolet Observations with the Voyager Ultraviolet Spectrometer: New Evidence for Interacting Winds in Symbiotic Systems
Leahy, D. A.; Li, P. S.
The interacting winds model has been used to explain many observational phenomena of symbiotic systems and planetary nebulae successfully. New observational results on seven symbiotic systems, obtained by the ultraviolet spectrometer (UVS) on board of spacecrafts Voyager 1 and Voyager 2, provide strong new evidence supporting the interacting winds…
The Luminosity Function for L > L* Galaxies at z > 3
Bershady, Matthew A.; Majewski, Steven R.; Koo, David C. +2 more
Through the use of multiband (U,BJ,RF,IN) photometry we have isolated high-redshift (3.0<z<3.5) galaxy candidates in surveys of 1.27 deg2 to RF=21.25 and 0.02 deg2 to RF=23.5. Our pool of candidates constrains the nature of the 3.0<z<3.5 luminosity function ov…