6 papers
Photospheric composition of the carbon-rich 21 micron post-AGB stars IRAS 22223+4327 and IRAS 04296+3429
Leen Decin, Hans Van Winckel, Christoffel Waelkens +1
We present a detailed chemical analysis on the basis of high-resolution, high signal-to-noise optical spectra of two post-AGB objects IRAS 22223+4327 and IRAS 04296+3429. Both disp…
Variability and nature of the binary in the Red Rectangle Nebula
C. Waelkens, H. Van Winckel, L. B. F. M. Waters +1
We present new observations of the central binary inside the Red Rectangle nebula. The detection of zinc in the optical spectrum confirms that the peculiar photospheric abundances…
Lines of Circumstellar C2, CN, and CH+ in the Optical Spectra of Post-Agb Stars
Eric J. Bakker, David L. Lambert, Ewine F. van Dishoeck
Recent optical spectra of post-AGB stars show the presence of C2, CN, and CH+ originating in the circumstellar shell. We present here new, higher resolution spectra which provide c…
The 218 day period of the peculiar late B-type star HD 101584
Eric J. Bakker, Henny J. G. L. M. Lamers, L. B. F. M. Waters +1
We have searched for periodicity in the photometric and spectroscopic variations of the enigmatic star HD 101584 and found a long-term variability on a typical time scale of 1700 d…
Detection of C2, CN, and NaID absorption in the AGB remnant of HD56126
Eric J. Bakker, L. B. F. M. Waters, Henny J. G. L. M. Lamers +2
We present the detection of molecular absorption lines in the optical spectrum of the post-AGB star HD56126. The C2 Phillips A^{1}Π_{u}-X^{1}Σ^{+}_{g} (1,0), (2,0), and (3,0); Swan…
The velocity gradient in the pseudo-photosphere of the peculiar supergiant HD101584
Eric J. Bakker
In this paper preliminary results are presented based on a study of the low and high resolution ultraviolet spectrum of the peculiar supergiant (post-AGB star) HD101584. By a compa…