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A proper motion study of the globular cluster M 10
Chen, L.; Geffert, M.; Wang, J. J. +2 more
We present the first proper motion study of M 10 (NGC 6254). Absolute proper motions of about 532 stars in the field of the globular cluster M 10 were determined with respect to Hipparcos and ACT reference stars. In addition to photographic plates of Bonn and Shanghai also wide field CCD observations as second epoch plates were used. The wide fiel…
Extreme-Ultraviolet Flares in an F2 Star
Mullan, D. J.; Mathioudakis, M.
We report on the coronal properties of two early F dwarfs. For both stars, spectroscopic data reveal a hot corona with material at temperatures as high as 107.1-107.2 K. The EUV photometric observations of one of the stars (HR 120: F2) reveal two large flares with rapid decay times. The rapid decays are in striking contrast w…
Shaping of elliptical planetary nebulae. The influence of dust-driven winds of AGB stars
Höfner, Susanne; Reimers, Christian; Dorfi, Ernst A.
We calculated a model to investigate the shaping of a PN morphological group, i.e. elliptical PNe, in terms of the so-called Interacting Winds Model. The angle-dependent mass loss generated by a dust driven wind due to a slow rotation of the AGB star is an effective way for the shaping of PNe. The matter which is more concentrated in the equatoria…
The Ultraviolet Spectrum of VV Cephei Out of Eclipse
Bennett, Philip D.; Bauer, Wendy Hagen
The International Ultraviolet Explorer (IUE) satellite observed VV Cephei (M2 Iab+B?) over nearly a full 20.3 year orbital period, but all the observations were obtained outside total eclipse. Egress of the chromospheric eclipse was the only portion of the eclipse observed by IUE. We have examined all 124 high-resolution IUE spectra of VV Cephei a…
The SOHO-Stellar Connection
Ayres, Thomas R.
The `solar- stellar connection' bridges the daytime and nighttime communities; an essential link between the singular, but detailed, views of our Sun, and the broad, but coarse, glimpses of the distant stars. One area in particular - magnetic activity - has profited greatly from the two way traffic in ideas. In that spirit, I present an evolutiona…
Simulation of Nonlinear Waves in a Magnetic Flux Tube near the Quiet Solar Photospheric Network
Sakai, J. I.; Mizuhata, Y.; Kawata, T. +1 more
Recent high-resolution observations from photospheric magnetograms made with the SOHO/Michelson Doppler Imager instrument and Swedish Vacuum Solar Telescope on La Palma showed that magnetic flux tubes in the quiet photospheric network of the solar photosphere are highly dynamic objects with small-scale substructures. We investigate nonlinear waves…
Spectroscopic confirmation of a white dwarf companion to the B star 16 Dra
Barstow, M. A.; Burleigh, M. R.
Using an Extreme Ultraviolet Explorer (EUVE) spectrum, we confirm the identification of a white dwarf companion to the B9.5V star 16 Dra (HD150100), and constrain its surface temperature to lie between 29,000 K and 35,000 K. This is the third B star + white dwarf non-interacting Sirius-type binary to be confirmed, after y Pup (HR2875, HD59635) and…
Vertical motions in the disk of NGC 5668 as seen with optical Fabry-Perot spectroscopy
Battaner, E.; Jiménez-Vicente, J.
We have observed the nearly face-on spiral galaxy NGC 5668 with the TAURUS II Fabry-Perot interferometer at the William Herschel Telescope using the Hα line to study the kinematics of the ionized gas. From the extracted data cube we construct intensity, velocity and velocity dispersion maps. We calculate the rotation curve in the innermost 2 arcmi…
CaII K Emission-Line Asymmetry among Red Giants Detected by the ROSAT Satellite
Smith, Graeme H.; Shetrone, Matthew D.
Spectra of the Ca II H and K lines are reported for a number of field giants from which soft X-ray emission was detected by the ROSAT satellite. Several of these stars are RS CVn systems and exhibit very strong Ca II emission. The majority of the noninteracting giants in the sample have MV>-2.0, as determined from Hipparcos parallaxe…
Kinematics and morphology of the narrow-line region in the Seyfert galaxy NGC 1386
Dietrich, M.; Wagner, S. J.; Rossa, J.
We present a high spatial and spectral resolution 2-D echelle spectrogram of the Narrow-Line Region in the Seyfert 2 galaxy