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Stellar Photometry with the Hubble Space Telescope Wide-Field/Planetary Camera: A Progress Report
Schneider, Donald P.; Lauer, Tod R.; Faber, S. M. +16 more
We describe the prospects for the use of the Wide-Field/Planetary Camera (WFPC) for stellar photometry. The large halos of the point- spread function (PSF) resulting from spherical aberration and from spatial, temporal, and color variations of the PSF are the main limitations to accurate photometry. Degradations caused by crowding are exacerbated …
The Halo Planetary Nebulae M 2-29 and BB-1
Pena, M.; Torres-Peimbert, S.; Ruiz, M. T.
Spectrophotometric data for the two planetary nebulae are given and compared to the data for a well-understood type of planetary nebula (PN) for classification and measurements of abundances. M 2-29 and BB-1 were observed in the wavelength ranges of 3500-5000 and 6000-7500, and the visual calibrated spectra and emission-line fluxes are given along…
IUE Observations of NGC 1068: The Extremely Luminous Starburst Knots
Bruhweiler, F. C.; Truong, K. Q.; Altner, B.
We present a complete study of the UV characteristics of the starburst knots in the inner 3 kpc region of NGC 1068 mapped by the International Ultraviolet Explorer (IUE) satellite. These knots likely represent the most luminous H II regions yet studied at optical and ultraviolet wavelengths. Comparisons indicate the brightest UV knot, knot 1, is 3…
Observations of the Peculiar Object MWC 560 in Outburst
Dapergolas, A.; Michalitsianos, A. G.; Kontizas, M. +4 more
The results of ultraviolet spectroscopy, photoelectric photometry, and supplemental high-resolution H(alpha) spectroscopy of a photometric outburst of MWC 560 are discussed. Ultraviolet spectra are shown to be consistent with the ejection of an optically thick shell that produced strong absorption blends of Fe II and Cr II. The velocities reported…
Fe II Emission Lines. I. Chromospheric Spectra of Red Giants
Judge, P. G.; Jordan, C.
A 'difference filtering' algorithm developed by Ayers (1979) is used to construct high-quality high-dispersion long-wavelength IUE spectra of three giant stars. Measurements of all the emission lines seen between 2230 and 3100 A are tabulated. The emission spectrum of Fe II is discussed in comparison with other lines whose formation mechanisms are…
Comparison of observed and calculated implanted ion distributions outside Comet Halley's bow shock
Coates, A. J.; Neugebauer, M.; Gombosi, T. I. +2 more
This paper compares calculated and measured energy spectra of implanted H+ and O+ ions on the assumption that the pickup geometry is quasi-parallel and about 1% of the waves generated by the cometary pickup process propagate backward (toward the comet). The model provides a good description of the implanted O+ and …
X-Ray Emission from Hybrid-Chromosphere Stars
Brown, Alexander; Drake, Stephen A.; Linsky, Jeffrey L. +1 more
The observations of hybrid stars made by the Exosat X-ray satellite are considered, and emphasis is placed on the hybrid star alpha TrA. Attention is focused on the determination of the column density of IS hydrogen toward the stars in order to interpret X-ray observations of stellar coronal emission. The coronal properties of alpha TrA are discus…
The Many Faces of F Stars: A Rotational Modulation Study of Capella, Procyon, and Caph with the International Ultraviolet Explorer
Ayres, Thomas R.
Far-UV spectroscopy of the F stars Capella, Procyon, and Caph is reported. Although all three stars are regard as chromospherically 'active', none exhibited any sensible rotational modulations, indicating a smooth surface distribution of chromospheric emission. Balancing this nonsolar behavior are a variety of puzzling differences among the three …
Ultraviolet and Optical Spectroscopy of the R Aquarii Symmetrical Jet
Hollis, J. M.; Kafatos, M.; Michalitsianos, A. G. +2 more
The first ultraviolet spectrum of the southwest (SW) component of the symmetrical jet in the R Aquarii binary system has been obtained in the range 1200-2000 A with the IUE. These results are compared to more encompassing spectra of the central H II region taken at the same time and also similar spectra of the northeast (NE) jet component obtained…
Mass Outflow in the Nearby Proto--Planetary System beta Pictoris
Grady, C. A.; Kondo, Yoji; Bruhweiler, Frederick C.
Previous spectral studies of circumstallar dust around the nearby, candidate proto-planetary system, Beta Pictoris, has detected only infalling gas. The lack of detectable mass outflow has been critical in the interpretation of the origin of the circumstellar gas and in our understanding of the evolutionary status of the Beta Pictoris system. IUE …