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The Greatly Expanded IUE Spectrum of the Planetary Nebula NGC 2371-2 and Its Central Star
Feibelman, Walter A.
Early IUE low-dispersion SWP and LWR spectra have been reexamined by means of refined current data reduction routines. These spectra contain much more information than was reported in 1981. A high-dispersion SWP spectrum was obtained in 1994 from which more than 80 emission and absorption features were identified, and log Ne = 3.0 +/- 0…
Ultraviolet and Optical Observations of Hen 1213, Hen 1341, and Hen 1761
Feibelman, W. A.; Gutiérrez-Moreno, A.; Moreno, H. +1 more
We present UV observations of the symbiotic stars Hen 1213, Hen 1341, and Hen 1761, made almost simultaneously with optical observations during 1995; previous optical observations were made during 1987 and 1991. The UV spectrum of Hen 1213 was badly affected by background radiation, and only a rough description of the spectrum could be given here;…
The Extremely Active Single Giant 1E 1751+7046 = ET Draconis: Revised Properties and a Reevaluation of Its Evolutionary Status
Guinan, Edward F.; Hrivnak, Bruce J.; Fekel, Francis C. +1 more
New spectroscopic observations have resulted in significant revisions to several of the orginally published properties of the X-ray bright, chromospherically active star 1E 1751+7046: the spectral classification has been revised from K5 IV to K0 III, v sin i from 30-40 km s-1 to 23 km s-1, and the reported nondetection of the…
Convection, Thermal Bifurcation, and the Colors of A Stars
Simon, Theodore; Landsman, Wayne B.
Broadband ultraviolet photometry from the TD-1 satellite and low-dispersion spectra from the short wavelength camera of IUE have been used to investigate a long-standing proposal of Böhm-Vitense that the normal main-sequence A and early-F stars may divide into two different temperature sequences: (1) a high-temperature branch (and plateau) compris…
The FUOR characteristics of the PMS star BN Orionis inferred from new spectroscopic and photometric observations
de Winter, D.; van den Ancker, M. E.; Tjin A Djie, H. R. E. +3 more
BN Ori is a young emission-line star with a peculiar light curve. During the first half of this century the star showed strong irregular brightness- variations, similar to those of Herbig Ae stars. In the current half of the century the light curve resembles that of a FU Ori-object (FUOR, after Ambartsumian 1971). It can be characterised by an ini…
Implications of Proton Anisotropy Development Observed by the ERNE Instrument During the 9 July 1996 Solar Particle Event
Laitinen, T.; Vainio, R.; Torsti, J. +1 more
We analysed the solar particle event following the 9 July 1996 solar flare. High-energy protons were detected by the ERNE instrument on board SOHO. Anisotropy of arriving protons revealed very peculiar non-monotonic development. A short period of almost isotropic distribution was imbedded into the prolonged period of beam-like distribution of 14-1…
Temperature and Velocity Diagnostics of the Red Rectangle from UV Spectra of CO and C I
Lauroesch, James T.; Sitko, Michael L.; Glinski, Robert J. +1 more
The UV spectrum of the Red Rectangle and its central source, HD 44179, was examined using the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST). Spectra have been obtained of the 0-0, 0-1, and 0-2 vibronic bands of the CO fourth positive system, the 1657 Å C I multiplet, and the 1931 Å C I line. All of the lines and b…
Redshifts of galaxies close to bright QSO lines of sight
Bowen, David V.; Blades, J. Chris; Osmer, Samantha J. +1 more
To expand the known number of low-redshift galaxies lying close to bright (V<17.2) QSO lines of sight, we have identified 24 galaxies within 11 arcmin of nine QSOs which have been observed with the Hubble Space Telescope (HST). Galaxies are found between redshifts of 0.0114 and 0.145 and lie between 39 and 749h^-1kpc from QSO sightlines. Knowin…
Structure and dynamics of the nuclear region of the spiral galaxy NGC 7217
Sil'chenko, O. K.; Zasov, A. V.
The gas velocities and brightness distribution in the inner region of NGC 7217 are analyzed. This galaxy has a regular axially symmetric shape with flocullent spiral arms that have a system of three distinct rings (outer, inner, and nuclear) - a structure that is rarely observed in the absence of a bar. Observations on the 6-m telescope of the Spe…
Optical performances of the Ultraviolet Coronagraph Spectrometer of the Solar Heliospheric Observatory
Fineschi, Silvano; Romoli, Marco; Naletto, Giampiero +6 more