Search Publications
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…
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…
The Program to Link the HIPPARCOS Reference Frame to an Extragalactic Reference System Using the Fine Guidance Sensors of the Hubble Space Telescope
Benedict, G. F.; Franz, O. G.; Hemenway, P. D. +19 more
The Hipparcos Satellite Mission has produced positions, proper motions, and parallaxes of unprecedented accuracy for 118,000 stars. For the positions and proper motions to represent true directions and physical motions in space, they must refer to an accurate realization of a nonrotating (inertial) reference frame. One of the major problems confro…
Ultraviolet interstellar linear polarization. IV. Cross-calibration between the Wisconsin ultraviolet photo-polarimeter experiment and the faint object spectrograph.
Martin, P. G.; Whittet, D. C. B.; Clayton, Geoffrey C. +6 more
The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) and the Faint Object Spectrograph (FOS) started gathering UV spectropolarimetry in 1990. Each observed a wide range of polarimetrically interesting objects before being retired. This paper examines the polarimetric calibration of each instrument and compares the absolute calibrations t…
IUE and Voyager Observations of the Unusual Cataclysmic Variable S193
Garnavich, Peter; Szkody, Paula; Holberg, Jay +2 more
UV observations of S193 were obtained with Voyager and the IUE satellite during both high and low states of this unusual object. Voyager only detected the source during the high state, where the continuum looks similar to the novalike IX Vela and dwarf novae at outburst. The IUE spectra at the high state show deep absorption lines, but the line ra…
Ultraviolet Color-Magnitude Diagram Studies of Intermediate Age Large Magellanic Cloud Star Clusters.I.NGC 1783
Cole, Andrew A.; Freedman, Wendy L.; Gallagher, John S., III +1 more
We have imaged the billion-year-old Large Magellanic Cloud star cluster NGC 1783 with the Wide Field/Planetary Camera 2 (WFPC2) in order to obtain broadband photometry at 1600 and 3300 Angstroms. We have identified for the first time the individual stars responsible for the unexpectedly strong ultraviolet light of intermediate-age stellar systems.…
Chromospherically Active Stars. XVI. The Double-Lined Binary 42 Capricorni
Fekel, Francis C.
New spectroscopic observations of the chromospherically active binary, 42 Capricorni, have resulted in the detection of lines of the secondary, improved orbital elements, and the determination of fundamental properties of the components. 42 Cap has an orbital period of 13.174004 d, an eccentricity of 0.176, and a mass ratio A/B of 1.375. No eviden…
High-Resolution V, I, and K-Band Imaging of Faint Field Galaxies from the HST Medium-Deep Survey
Windhorst, Rogier A.; Close, Laird M.; Mutz, Steven B. +2 more
We present infrared and optical data for 13 galaxies with 16.0≤I≤21 mag previously observed with the Hubble Space Telescope as part of a study of 300 galaxies from the Medium-Deep Survey. We observed four of these galaxies at the Steward Observatory 90" and 61" telescopes in the K band (λeff=2.2 µm) with a tip-tilt secondary mirro…