Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Instrumentation
Observations And Analysis Of The Aquarii Jet, Menas Kafatos, Andrew G. Michalitsianos
Observations And Analysis Of The Aquarii Jet, Menas Kafatos, Andrew G. Michalitsianos
Mathematics, Physics, and Computer Science Faculty Books and Book Chapters
Ultraviolet, optical and radio observations of the symbiotic star R Aquarii are discussed in the light of the discovery of a bright radio and optical jet from this star. The star is probably a binary with a period of 44 years. The VLA maps of the jet reveal a protruding structure extending-10 arc sec from the central radio source with a position angle virtually identical to that of the optical jet observed at Lick. We interpret the observations of R Aqr as indicating the existence of an accretion disk around an unseen companion. The hot subdwarf has effective temperature ,(65,000 …
Uv Emission From The M1 Supergiant Tv Gem, Andrew G. Michalitsianos, Menas Kafatos
Uv Emission From The M1 Supergiant Tv Gem, Andrew G. Michalitsianos, Menas Kafatos
Mathematics, Physics, and Computer Science Faculty Books and Book Chapters
Low and high dispersion ultraviolet spectra were obtained of the Ml supergiant TV Gem with IUE. Previous IUE observations of this late type supergiant revealed unexpected W continuum emission, perhaps arising from an early B companion. Low resolution spectra obtained approximately one year apart suggest that the strong Si I11 in-combination perhaps with 0 I at wavelengths % A1300 A varies considerably with time. Large variation the column density is required to explain these changes. Sporadic mass expulsion with mass loss rates dM/dt * 10-5 S y r - l from the M supergiant could lead to a dense circumstellar …
Ci Cygni Since The 1980 Eclipse, R. E. Stencel, Andrew G. Michalitsianos, Menas Kafatos
Ci Cygni Since The 1980 Eclipse, R. E. Stencel, Andrew G. Michalitsianos, Menas Kafatos
Mathematics, Physics, and Computer Science Faculty Books and Book Chapters
Following the 1980 eclipse of the 855 day period symbiotic binary CI Cyg, we were confronted with a data set showing high excitation resonance lines which were largely uneclipsed but brightening on an orbital timescale, and intercombination lines exhibiting pronounced but nontotal eclipses and which were fading on an orbital timescale. Our model invoked a low density dissipating nebula surrounding the hot companion to explain the intercombination lines, and a shock between stellar winds to interpret the resonance lines. Subsequent synoptic observations have revealed continuing changes in the W emission line fluxes, consistent with those described above, except for the …