Search Publications
Hβ photometry of southern CP2 stars: is the uvbybeta luminosity calibration also valid for peculiar stars?
Vogt, N.; Paunzen, E.; Maitzen, H. M. +1 more
We present Hβ photometry of 233 southern CP2 stars (covering the magnetic Ap stars according to the definition by Preston 1974) brighter than V < 8.5 mag from the list of Bidelman & MacConnell (1973). Absolute magnitudes derived from this photometry together with already existing uvby photometry is confronted with Hipparcos results availabl…
Physical parameters of EUV explosive events
Doyle, J. G.; Pérez, M. E.
Previously published results of EUV explosive events and electron density enhancements in the solar transition region are revised. An attempt has been made to correlate both observational phenomena, and to associate the observed density enhancements to magnetic reconnection sites. The corresponding local magnetic field strength in these sites is e…
An estimation of the shape and temporal variation of the solar wind sonic, Alfvénic and fast magnetosonic surfaces
Moussas, X.; Exarhos, G.
In this work we find the shape and dimension of the solar wind transition surfaces, namely the slow (sonic), the fast magnetosonic and the Alfvén surface, as a function of heliospheric latitude using actual experimental data from Ulysses spacecraft during its first pole to pole journey. We also give the temporal variation of the radius of these su…
Distance and absorption features in the CG 30/CG 31/CG 38 complex
Knude, J.; Nielsen, A. S.
We report a possible confirmation of the short 200 pc distance to the cometary globules CG 30/31/38 suggested by a previously discussed (V - I) - V diagram to Vlim ~ 20 mag. New 2 magnitudes deeper V and I photometry centered on CG 31A indicate the presence of visual extinction A_V = 5\fm6 at 200 pc. In addition, we may have measured an…
Kinematics versus X-ray luminosity segregation in the Hyades
Makarov, V. V.
State of the art Tycho-2 proper motions of bona fide Hyades members are used in combination with the ROSAT X-ray survey of this open cluster in Stern et al. (1995) to study the internal velocity dispersion versus X-ray luminosity by the classical convergent point method. It is shown in this paper for the Hyades members with B-V below 0.7 mag that …
17 µm imaging of eta Carinaea: an onion-like structure for the lobes?
Pantin, E.; Le Mignant, D.
We have obtained a 17 mu m image of the eta Carinae nebula with a signal to noise ratio never reached before. Once deconvolved, the spatial resolution is of the order of 0.5\arcsec. The ring and arclike structures seen at 17 mu m are very similar to those observed at 12.5 mu m; however the intensity maximum is located elsewhere in a dense cold str…
Line-profile variation in tau Herculis
Masuda, Seiji; Hirata, Ryuko
Based on a time series of high-resolution spectra at He I lambda 4471 and Mg Ii lambda 4481, we have detected the line-profile variation of
The UV (IUE) spectrum of the planetary nebula PC 11 (HD 149427)
Pottasch, S. R.; de Martino, D.; García-Lario, P. +2 more
The UV spectrum of PC 11 is found to show variations in the strength of the O III] 1666Ä , N III] 1750Ä and C III] 1909Ä emission lines. The detection of continuum emission in the wavelength interval 2650Ä to 3200Ä indicates that the central star of PC 11 has an early F-type dwarf companion. The very low level of UV continuum in the wavelength int…
The Fe II excitation mechanism in KQ Puppis
Johansson, S. G.; Redfors, A.
We discuss different excitation processes behind the Fe II emission lines in the IUE spectrum of KQ Puppis (Boss 1985), a VV Cephei type of spectroscopic binary. Several papers have been published on the subject suggesting a number of processes behind the strong Fe II emission lines. We propose that there are two processes operating: selective pho…
ISO far-infrared observations of rich galaxy clusters. III. Abell 2029, Abell 2052, Abell 2142
Nørgaard-Nielsen, H. U.; Pedersen, K.; Hansen, L. +3 more
A sample of five rich galaxy clusters has been mapped by ISO at 60 mu m, 100 mu m, 135 mu m, and 200 mu m using the PHT-C camera. In previous papers Abell 2670 and Sérsic 159-03 were discussed. Here we present the results for Abell 2029, Abell 2052, and Abell 2142. The conclusion of the survey is that the relatively small fields (~60 square arc mi…