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The mid-infrared color of NGC 6946.
Helou, G.; Lord, S. D.; Malhotra, S. +10 more
We analyze the new mid-infrared maps of NGC 6946 for variations in the color ratio of the 7-to-15µm emission. Our preliminary findings are that this mid-infrared color is remarkably constant between arms and inter-arm regions, and as a function of radius in the disk, excluding the nuclear region. As surface brightness ranges by more than an …
Theoretical amplitudes of solar g-modes.
Andersen, B. N.
This work presents predictions on the amplitudes of solar g-modes. It is based on the assumption that convective overshoot into the convectively stable interior generates gravity waves. Based on this assumption it is possible to estimate values for the amplitude of the g-modes below the solar convection zone. Numerical simulations, giving the tran…
The regular structure of shock-accelerated ~40-100keV electrons in the high latitude heliosphere.
Simnett, G. M.; Tappin, S. J.; Roelof, E. C.
The passage of Ulysses through the high latitude heliosphere has given us a new insight into the interplanetary dynamical processes which are occurring, at any rate near solar minimum, in the heliosphere above the streamer belt. We report here observations of ~40-100keV electrons and ~0.5MeV protons detected by HI-SCALE from 1992-96. Apart from a …
ULYSSES observations of pressure-balance structures in the polar solar wind.
Forsyth, R.; Balogh, A.; McComas, D. J. +4 more
Throughout its high-latitude excursion Ulysses has observed several types of solar wind structures. In addition to structures such as Alfven waves, compressional features, and microstreams, the solar wind also contains low contrast pressure-balance structures (PBSs). The PBSs are marked by an anti-correlation of the plasma and field pressures; the…
GX340+0 with EXOSAT: its correlated X-ray spectral and timing behaviour.
van der Klis, M.; Kuulkers, E.
We report on three observations of the Z source GX340+0 performed with EXOSAT during 1985 and 1986. In two observations the source was in the horizontal branch and the upper part of the normal branch of the Z pattern in the X-ray colour-colour diagram, while in the third observation it was in the normal and flaring branches. We found that the hori…
Observations of the central star and nebula of Abell 65.
Walsh, J. R.; Walton, N. A.
Imaging and spectrophotometry of the low surface brightness planetary nebula Abell 65 and its eclipsing binary central star are presented. The spectrum of the central star is remarkable in showing H and He lines in emission, similar to the spectra of cataclysmic variables. This is the second PN central star, after HFG 1, to show such stellar line …
The abundance of boron in evolved A- and B-type stars.
Lambert, D. L.; Venn, K. A.; Lemke, M.
Boron abundances in A- and B-type stars may be a successful way to track evolutionary effects in these hot stars. The light elements - Li, Be, and B - are tracers of exposure to temperatures more moderate than those in which the H-burning CN-cycle operates. Thus, any exposure of surface stellar layers to deeper layers will affect these light eleme…
The central star of LoTr5 revisited.
Jasniewicz, G.; Thevenin, F.; Monier, R. +1 more
We report on new photometric and spectroscopic observations carried out in 1994 of the late-type star HD112313 in the binary nucleus of the planetary nebula LoTr5. From comparison with model spectra we derive a gravity logg=2.7+/-0.5 and an effective temperature T_eff_=5250+/-200K, in full agreement with a spectral type G5III. Iron is found to be …
ULYSSES observations of open and closed magnetic field lines within a coronal mass ejection.
Balogh, A.; Forsyth, R. J.; Goldstein, B. E. +7 more
During the rapid passage from the Sun's south to north polar regions, the Ulysses spacecraft encountered in February 1995, at 24°S, a coronal mass ejection (CME) exactly at the time when it crossed from high speed solar wind coronal hole flow into low speed streamer belt flows. We have investigated this CME, which was superimposed on an energetic …
MWC 314: a high-luminosity peculiar Be star.
Miroshnichenko, A. S.
New broad-band multicolor photometry and optical spectroscopy of the emission-line star MWC 314= BD +14deg3887 as well as a study of its ultraviolet spectrum are reported. It is shown that the star exhibits photometric variability with a quasi-regular component. Main parameters of the star and its envelope are determined from both the spectral ene…