We present the results of new time-series photometric observations of 29 pre-white dwarf stars of PG 1159 spectral type, carried out in the years 2014-2022. For...
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PublicationThe GW Vir Instability Strip in Light of New Observations of PG 1159 Stars: Discovery of Pulsations in the Central Star of A72 and Variability of RX J0122.9-7521
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PublicationThe impact of supernova fragments on the evolution of multisupernova remnants
Analytical approximations and 2D hydrodynamical simulations are used to examine the interaction of supernova fragments with the internal structure of large...
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PublicationThe influence of internal gravity waves on the light elements depletion among F-type stars
It is proposed that the Li abundances in F-type stars can be affected by the weak mixing generated by internal gravity waves since the absence of Li is so...
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PublicationThe intermediate age open cluster NGC 7044
A photometric analysis is conducted of the open cluster NGC 7044, on the basis of UBVR CCD observations of 896 stars in the cluster field. Reddening and...
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PublicationThe Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. I. Survey Overview and First Results for Andromeda I
An optical monitoring survey in nearby dwarf galaxies was carried out with the 2.5 m Isaac Newton Telescope. Fifty-five dwarf galaxies and four isolated...
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PublicationThe mass and helium discrepancy in massive stars: the case Vela X-1.
A NLTE-analysis is presented of high S/N spectra of the optical component of the standard massive X-ray binary Vela X-1. In combination with the orbital...
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PublicationThe Missing Link? Discovery of Pulsations in the Nitrogen-rich PG 1159 Star PG 1144+005
Up to 98% of all single stars will eventually become white dwarfs-stars that link the history and future evolution of the Galaxy, and whose previous evolution...
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PublicationThe nature of the Kleinmann-Low nebula
Recent data on, and interpretations of the Kleinmann-Low nebula are examined. It is suggested that associated high velocity gas is radiatively accelerated by a...
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PublicationThe oldest galactic open clusters - New CCD photometry and colour-magnitude diagrams
The paper presents CCD photometry for stars in three fields centered on the old open cluster NGC 188 and in four fields on the intermediate-age cluster NGC 7789...