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The ISO spectrum of the planetary nebula NGC 6302. I. Observations
Pottasch, S. R.; Beintema, D. A.
The spectrum of the planetary nebula NGC 6302 is presented, as it was observed by the ISO short-wavelength spectrometer. The IUE spectrum observed at the same position with the same aperture is also presented.
Metallicity-dependent effective temperature determination for eclipsing binaries from synthetic UVBY Strömgren photometry
Westera, P.; Buser, R.; Lastennet, E. +1 more
Strömgren synthetic photometry from an empirically calibrated grid of stellar atmosphere models has been used to derive the effective temperature of each component of double lined spectroscopic (SB2) eclipsing binaries. For this purpose, we have selected a sub-sample of 20 SB2s for which (b-y), m_1, and c_1 individual indices are available. This n…
Microscopic diffusion and subdwarfs
Morel, P.; Baglin, A.
The recent distance determinations by HIPPARCOS have allowed to locate very precisely a reasonable set of subdwarfs in the HR diagram. A detailed comparison with evolutionary models is now possible and it has been recently claimed that the observed lower part of the main-sequence is cooler than the computed one. In this paper we show that microsco…
Long-term coherent variations in the WR system EZ Canis Majoris: the binary scenario revisited
Koenigsberger, G.; Ivanov, M. M.; St. -Louis, N. +2 more
An analysis of seven different spectroscopic and eight photometric sets of observations of the WN5 star HD 50896=EZ CMa, distributed over more than 15 years is used to refine the known 3.76 days period. The value of P = 3.7650 +/- 0.0001 d yields variations which have coherent phase-dependence. Although not conclusive, this coherence in the 3.7650…
Time-resolved HST and IUE UV spectroscopy of the intermediate polar FO AQR
Mukai, K.; Gänsicke, B. T.; de Martino, D. +4 more
Time resolved spectroscopy of the Intermediate Polar FO Aqr reveals the presence of multiple periodicities in the UV range. A strong orbital modulation dominates both continuum and emission line flux variabilities, while line velocity motions are only detected at the rotational frequency. A prominent orbital periodicity is also observed in coordin…
ISO observations of globular clusters
Eyres, S. P. S.; Evans, A.; Odenkirchen, M. +2 more
We report ISO observations of globular clusters, from which we derive new upper limits on the masses of dust therein. Our observations do not confirm the claimed detection of dust in 47 Tuc by Gillett et al. (1988) and our limits generally support previous conclusions that globular clusters are deficient in intra-cluster dust grains. We find that …
The 10 GHz-10 THz spectrum of a normal spiral galaxy
Braine, J.; Hughes, D. H.
We present a complete FIR spectral energy distribution of a normal spiral disk. A full grating scan, from 43-189 mu m, centered on the nucleus of NGC 4414 was made with the ISO Long Wavelength Spectrometer (LWS). The mid-IR to millimeter continuum of NGC 4414 can be modeled with thermal dust emission from a warm component at 69 K and a cool compon…
Mid-infrared spectral images of planetary nebulae with ISOCAM
Rouan, D.; Siebenmorgen, R.; Cesarsky, D. +5 more
This paper presents the results of ISOCAM-CFV spectral images between 5 and 16.5 mu m of the planetary nebulae, NGC 6543, NGC 7027, NGC 6302, NGC 6720, BD+30degr 3639, VY 2-2, and of the proto-planetary nebula CRL2688. All the nebulae, except VY 2-2 are spatially resolved in the continuum and in the different spectral features. Integrated CVF spec…
Dynamics of solar active region loops
Ichimoto, K.; Hara, H.; Matthews, S. A. +1 more
It has been frequently observed that in solar active regions the measured line widths are larger than those based on thermal equilibrium widths. This excess width (characterised as non-thermal velocity, Vnt) has been proposed as a signature of the heating mechanism. The behaviour of the Vnt at coronal temperatures has not pro…
Proton and hydrogen temperatures at the base of the solar polar corona
Heinzel, P.; Wilhelm, K.; Tu, C. -Y. +2 more
The SUMER (Solar Ultraviolet Measurements of Emitted Radiation) Spectrometer on SOHO (Solar and Heliospheric Observatory) has been used to observe the lines of the Lyman series (up to quantum numbers larger than 20) of hydrogen emitted in the solar atmosphere. The line shapes and intensities versus height are obtained near the limb from about -10\…