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The Spectra of IC 418 and IC 5117 from 1.5 to 1.75 Microns
Kwok, Sun; Zhang, C. Y.
Near-infrared spectra of planetary nebulae IC 418 and IC 5117 in the wavelength range 1.5-1.75 microns are reported. More than 10 members of the Brackett line series are detected superposed on a strong continuum. Analysis of the spectra shows that the observed flux ratios of the Brackett lines are in good agreement with the recombination line theo…
IUE observations of the shells of RR PIC and GK Per.
Evans, A.; Bode, M. F.; Duerbeck, H. W. +1 more
We present UV observations of the resolved shells of the old novae RR Pic (1925) and GK Per (1901). On the assumption that the RR Pic nebula is photoionized by the ultraviolet continuum emitted by the stellar remnant, we conclude that nitrogen is overabundant relative to solar in both the 'equatorial ring' and 'polar blob' regions; there are steep…
CCD observations of additional interstellar lines in stars associated with the VELA remnant and ETA Carinae nebulosity.
Wallerstein, George; Gilroy, Kalpana K.
Nine stars from the Vela Remnant and seven stars in the Eta Carinae complex are examined with CCD spectrograms with high signal-to-noise ratios for data regarding the optical interstellar lines. These data are supplemented by observations of objects with known high-velocity components and substantial interstellar Ti II lines. The CCD spectrograms …
Detection and measurement of double stars with the HIPPARCOS satellite - NDAC reductions
Evans, D. W.; Lindegren, L.; van Leeuwen, F. +1 more
The Hipparcos satellite has a predefined observing program given by an Input Catalogue with 118,000 entries. This includes about 10,000 members of known double or multiple systems (with separations above 0.1 arcsec and magnitude differences below 4-5), which will be observably non-single and thus need a more complex reduction procedure. Also, a si…
Dynamic phenomena on the RS Canum Venaticorum binary II Pegasi in August 1989. I. Observational data.
Bromage, G. E.; Doyle, J. G.; Linsky, J. L. +22 more
Observational results are given for two flares in Pi Pegasi that were detected by the GINGA and IUE satellites, as well as by ground-based Johnson U-band photometry and optical spectroscopy. The best-fitting results were obtained for a combination of a single-temperature plasma together with a power law; for a two-temperature model, the temperatur…
Variability in the UV resonance lines of the cataclysmic variable V795 Herculis (PG 1711+336).
Drew, Janet E.; Prinja, Raman K.; Rosen, Simon R.
Variability in the UV resonance lines from the cataclysmic variable V795 Her is investigated on the basis of a total of 28 IUE SWP low-resolution spectra. Significant line profile fluctuations are evident in the C IV 1549 and Si IV 1400 doublets on time-scales down to less than about 30 min. There is little or no evidence for changes in N V 1240. …
The Unusual Ultraviolet Chromospheric Spectrum of the R Coronae Borealis Star, V854 Centauri (NSV 6708), at Minimum Light
Judge, P. G.; Stanford, S. A.; Clayton, Geoffrey C. +2 more
Results are presented of IUE observations of a decline of the recently discovered R CrB star, V854 Cen. These observations are of particular interest because they include spectra taken at 7 mag below maximum light. The 'chromospheric' emission spectra show striking differences from UV spectra of other R CrB stars in decline. Strong emission appear…
The 1990 outburst of the recurrent nova V3890 Sgr observed with IUE.
Gonzalez-Riestra, R.
V3890 Sgr (Nova Sgr 1962) is one of the more recent examples of recurrent novae. Its second recorded outbursts took place in April 1990. IUE observations were obtained during the first month after the outburst. The UV spectra show the development of very broad emission lines with complex and variable profiles. Of particular interest is the "narrow…
The Ultraviolet Color Gradient in the Late-Type Spiral Galaxy M33
O'Connell, Robert W.; Bohlin, Ralph C.; Landsman, Wayne B. +3 more
The ultraviolet surface brightness and color distributions for the late-type spiral galaxy M33 are derived from images at 1520 and 2490 A that were obtained by the Ultraviolet Imaging telescope (UIT) on the Astro Spacelab mission. although the surface brightness shows a general decline with radius, the dominant spiral arms cause significant deviat…
The Luminosity of the Double-Mode Cepheid Y Carinae
Evans, Nancy R.
IUE spectra of the double-mode Cepheid Y Carinae have been used to determine the spectral type of the binary companion. From the companion spectral type (B9.O V), the absolute magnitude of the Cepheid is found to be -2.94 mag, with an estimated uncertainty of +/-0.3. This luminosity is in good agreement with that from the period-luminosity-color r…