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ISO Observations of Symbiotic Stars
Clavel, J.; Metcalfe, L.; Schulz, B. +8 more
A number of symbiotic stars have been observed with ISO. In addition to a number of emission lines, SWS observations of the symbiotic novae RR Tel and V1016 Cyg reveal prominent, broad 10 & 18 µm silicate dust features. The 10 µm features are similar to the crystalline silicate profiles seen in classical novae. There is some evidence that the …
Chemical Abundances of Planetary Nebulae: A UV to Far-IR Case Study of NGC 6153
Liu, X. -W.
The evolutionary state and fundamental parameters of metallic A-F giants
North, P.; Kunzli, M.; Erspamer, D.
Using Hipparcos parallaxes, we show that the metallic A-F giants found by Hauck on the basis of their high Delta m(2) index in Geneva photometry are on average more evolved than their non-metallic counterparts. Their mass distribution, rate of binaries and v sin i are shown to be incompatible with those of Am stars, so that they cannot be descenda…
First Results from ISO Spectra of Supernova Remnants Heavily Interacting with the ISM
Lutz, D.; Sturm, E.; Oliva, E. +2 more
ISO spectra of the supernova remnant RCW103 are presented. This object is the prototype of a SNR shock heavily interacting with dense ISM (probably a molecular cloud). The spectra are dominated by prominent lines and show very little continuum at λ < 40 µm suggesting that the 12 and 25 µm IRAS emission from these types of remnant could be domin…
A Compact Spectral Range and Matching Extreme-Ultraviolet Spectrometer for the Simultaneous Study of 1 × 104-2 × 107 K Solar Plasmas
Doschek, G. A.; Brown, C. M.; Feldman, U. +2 more
An EUV spectral range of less than 100 Å in first order has been found that includes sufficient spectral lines and critical combinations of lines in first and second order to permit dynamic and diagnostic investigations of the solar atmosphere with a relatively simple spectrometer. An optical design of such a spectrometer, based on the performance…
A New Method for Diagnostics of Solar Magnetic Fields and Flows from Time-Distance Analysis
Ryutova, Margarita; Scherrer, Philip
We propose a new method to obtain information on plasma flows and magnetic fields below the visible solar surface using time-distance measurements. The method is based on sine and cosine transforms of propagation times measured as a function of direction. The method allows one to sort out various characteristics of the subsurface medium, the flows…
Photometry from the HIPPARCOS Catalogue: Constant MCP Stars, Comparison and Check Stars
Adelman, S. J.
Photometry from the Hipparcos catalogue is used to verify the constancy of four magnetic CP stars, as well as the comparison and the check stars used for variability studies of normal and chemically peculiar B and A stars with the Four College Automated Photoelectric Telescope; variability in these stars can produce spurious results. A few of the …
Stellar atmospheric parameters for the giant stars MU Pegasi and lambda Pegasi
Smith, G.
Profiles of the strong lines Ca II 8542 Angstroms, and Mg I 8806 Angstroms, together with regions containing Ca I, Fe I and Fe II lines in the spectra of the G8 giant stars mu Peg and lambda Peg have been recorded at high resolution and with signal/noise >= 100. The wings of the strong lines and the full profiles of intermediate strength lines …
On the systematic accuracy of the equatorial UBV standards
Evans, D. W.; Oja, T.
Using photometric data from the TYCHO experiment of the HIPPARCOS mission the discrepancies in B-V between the different series of measurement of the equatorial UBV standards have been studied. Corrections to the data by Landolt (1983) and Menzies et al. (1991) have been derived. based on observations made with the ESA Hipparcos satellite.
Ultraviolet Observations of a Dynamic Event in the Solar Corona
Dwivedi, B. N.; Wilhelm, K.; Curdt, W. +1 more
The Solar Ultraviolet Measurements of Emitted Radiation instrument (SUMER) observations show high Doppler shifts and temporal variations in profiles of ultraviolet lines from low temperature gas in the corona above the active region NOAA 7974. The profiles indicate ≈ 100 km s-1 flows coming from an almost stationary source that appears …