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Two new color-selected magnetic DA white dwarfs.
Sion, E. M.; Green, R. F.; Boroson, T. A. +3 more
The discovery of two magnetic white dwarfs culled from blue star surveys is reported. The surveys were carried out with the Mount Lemnon 1.5-meter reflecting telescope attached to a two-holer polarimeter/photometer. Spectral observations of the objects, (PG 1533 - 057, and K813 - 14), indicate the presence of hydrogen and Zeeman components. On the…
IUE and optical spectral scans of U Sagittae : an analysis and comparison with U Cephei.
Plavec, M. J.; Dobias, J. J.
Recent optical and ultraviolet observations of U Sge are presented, and the results are compared with observations of U Cephei. The observations were carried out with: the International Ultraviolet Explorer (IUE) satellite; with the ITS scanner of the Lick Observatory; and with a Varo image-tube camera attached to a coude spectrograph. Comparison …
H-alpha variability in X-ray transient source X0331+53.
Iye, M.; Kodaira, K.
Spectroscopic observations of X0331+53 between October 1984 and March 1985 revealed that the equivalent width of Hα emission decreased by a factor of about four relative to that observed one year ago. This finding, in association with the decline of X-ray activity of the source reported by the EXOSAT group, is interpreted to support the binary mod…
Observations of RR Lyrae and X ARIETIS with the IUE satellite.
Bonnell, J. T.; Bell, R. A.
UV spectroscopic observations of RR Lyr and X Ari obtained at high and low dispersion using the LWR and SWP cameras of IUE on Jan. 25-28, 1980, are reported. The data are presented in tables and graphs and compared with the results of synthetic-spectrum calculations based on the VR photometric data of Manduca et al. (1981). Good agreement is obtai…
The 1984 eclipse of the symbiotic binary SY Muscae.
Lutz, J. H.; Kafatos, M.; Michalitsianos, A. G. +1 more
The authors present ultraviolet and optical observations of the 1984 eclipse of the symbiotic binary star SY Mus. The optical light curve shows a 627-day variation which is reflected in the intensity of the far-UV continuum (λ < 2000 Å) and in the intensities of all strong, permitted UV emission lines. This contrasts sharply with other eclipsin…
Time-resolved UV spectroscopy of BE Ursae Majoris.
Hutchings, J. B.; Cowley, A. P.
Far-ultraviolet spectra have been obtained of the eclipsing, hot subdwarf binary, BE UMa, with phase coverage in the 2.3-day orbital period concentrated near minimum light. No clearly phase-related spectral changes were found, but the UV continuum appeared to be in a highly variable state, with changes of a factor of two occurring on a time scale …
The August 1984 eclipse of 22 Vulpeculae.
Ake, T. B.; Parsons, S. B.; Hopkins, J. L.
The newly discovered eclipsing binary 22 Vul (G3 Ib-II + B9) was observed in and around the 1984 eclipse both with the IUE satellite and by photometrists at various ground-based observatories. The depth of total eclipse of the hot component was 0.05 mag in the V band, 0.14 in B, and 0.35 in U. Time of mideclipse is now established at JD2445942.3 (…
On the coronae of rapidly rotating star. V. The other stars.
Walter, F. M.
Results of Einstein X-ray observations of 25 stellar systems are presented. The systems observed include 15 spectroscopic binaries of which eleven were detected; nine were serendipitous detections, three of which may be new RS CVn systems. Coronal activity levels and their implications for these stars are discussed.
IUE observations of HD 164615.
Rucinski, S. M.
It is seen that HD 164615 with its spectral type F2 IV-V and (B - V) = 0.34 mag must be an exception to the rule that stars earlier than about F7 V cannot develop large spots. Abt, Bollinger and Burke (1983) found a periodic modulation of its brightness by 0.05 magnitude which they interpreted as resulting from the rotation of dark spots across th…
The ultraviolet spectrum of the planetary nebula M 3-27.
Feibelman, W. A.
The planetary nebula M3-27 was observed in the low-dispersion mode of the IUE satellite in the region 1150 A-3200 A. A fairly strong continuum was seen to extend down to 1150 A, superposed with a relatively small number of emission lines. A high electron density is inferred from forbidden O III but regions of lower density also exist. The ultravio…