Search Publications
Is the Galactic Halo Planetary Nebula PN G243-37.1 an ``O VI Sequence'' Variable Object?
Feibelman, Walter A.
Archival IUE spectra of the Galactic halo planetary nebula PN G243-37.1 have been reprocessed by the NEWSIPS routine. The new results show a much richer emission-line spectrum than has previously been reported. Several C iii, C iv, O v, and possibly O vi features were detected. P Cygni line profiles could not be identified with certainty. The He i…
Spectroscopy of the Cataclysmic Variable UU Aquarii: s-Waves and Bright Spots
Schlegel, Eric M.; Kaitchuck, Ronald H.; White, James C., II +1 more
This paper reports the results of UV and optical spectroscopy of the nova-like variable UU Aqr. There is a decrease in the light flux of both the optical and UV emission lines at phase ~0.95. This appears to be due to an occultation of an asymmetric accretion disk. The emission-line profiles seem to show the first half of the rotational disturbanc…
Analysis of the waves associated with the unusual interplanetary shock observed on day 109, 1992
Balogh, A.; Lucek, E. A.
On day 109 of 1992 Ulysses observed an extraordinary interplanetary shock at a time of extremely unusual interplanetary magnetic field conditions. The field was closely aligned with the radial direction for nearly a day ahead of the shock, suggesting that it was most likely to be a quasi-parallel shock. Unlike most interplanetary shocks, this shoc…
High-Excitation Emission Lines in the Far-Ultraviolet Spectrum of the Late A Star α Cephei
Ayres, Thomas R.; Simon, Theodore
The A7 V star α Cephei lies in a region of the Hertzsprung-Russell diagram that is generally thought to be devoid of solar-like magnetic activity. The far-ultraviolet spectrum of this star was observed with the Berkeley spectrograph during the 1996 ORFEUS-SPAS II mission. We detected emission lines of Si III, C III, and O VI in the 900-1200 Å inte…
Reprocessed UV pulses from the binary companions of X-ray pulsars
Dolan, J. F.; Boyd, P. T.; Percival, J. W. +3 more
A search for reprocessed X-rays causing UV pulsations in the companion stars to X-ray pulsars was carried out in a 200 Angstroms wide bandpass centered at 1450 Angstroms using the High Speed Photometer on the Hubble Space Telescope. We observed the systems A0535+26 = HD245770, 4U0900-40 (Vela XR-1) = HD77581, A1118-61 = He3-640, and 4U1145-619 = H…
Mid-infrared spectroscopy of obscured IRAS galaxies
Taniguchi, Yoshiaki; Sato, Yasunori; Kawara, Kimiaki +1 more
Spectra from 6 to 12 mu m are presented for the infrared galaxies NGC 1266, Arp 148, and IRAS 1713+53. Though they are not markedly luminous (<= 10(12) L_⊙), their IRAS colors are close to the colors of ultraluminous infrared galaxies, and thus indicative of heavy obscuration. The 6-12 mu m spectra are dominated by emission features of polycycl…
Dust Around Solar Mass Stars
Chary, R.; Zuckerman, B.; Becklin, E. E. +4 more
The DEBRIS project is a search for infrared excess around Sun-like main sequence stars, and other types of stellar targets, using the Infrared Space Observatory. Some results, calibration issues, and changes to our original program are presented. Future platforms for advancing this project after the conclusion of the ISO mission are indicated.
Polar plumes and fine-scale coronal structures - On the interpretation of coronal radio sounding data
Pätzold, M.; Bird, M. K.
Variations in total electron content at high heliographic latitudes, observed during the 1995 solar conjunction of the Ulysses spacecraft when the radio ray path was embedded in the southern coronal hole, were interpreted by Woo and Habbal [1997b] as polar plume structures extending to at least 30 solar radii from the Sun. Somewhat surprisingly, w…
Two spacecraft observations of transient shocks and ejecta in the interplanetary medium
González-Esparza, J. Américo; Bravo, Silvia
We compare Ulysses observations of 22 forward transient shocks (FTSs) and 11 ejecta during the first 19 months of its mission, with observations near Earth by IMP, in order to infer some properties of the propagation of these transient events in the interplanetary medium. We found that 13 of the 22 FTSs detected by Ulysses were also detected by IM…
Imaging Saturns dust rings using energetic neutral atoms
Krimigis, S. M.; Mitchell, D. G.; Roelof, E. C. +3 more
The intense populations of magnetically trap- ped, energetic charged particles that constitute the radiation belts of Saturn's inner magnetosphere are slowly transported towards the planet by radial diffusion processes. Many of these energetic particles interact with the rings of Saturn and ultimately are lost to the magnetospheric system. Energet…