000003899 001__ 3899
000003899 005__ 20190125155403.0
000003899 0247_ $$2DOI$$a10.3390/galaxies6040131
000003899 037__ $$aSCART-2019-0068
000003899 100__ $$aVan de Steene, G. C.
000003899 245__ $$aSpectroscopic and Photometric Variability of Three Oxygen Rich Post-AGB “Shell” Objects
000003899 260__ $$c2018
000003899 520__ $$aLight, color, and radial velocity data (2007–2015) for HD 161796, V887 Her, and HD 331319, three oxygen-rich post-AGB stars, have thus far not provided direct support for the binary hypothesis to explain the shapes of planetary nebulae and severely constrain the properties of any such undetected companions. The light and velocity curves are complex, showing similar periods and variable amplitudes. Nevertheless, over limited time intervals, we compared the phasing of each. The color curves appear to peak with or slightly after the light curves, while the radial velocity curves peak about a quarter of a cycle before the light curves. Thus it appears that these post-AGB stars are brightest when smallest and hottest. The spectra of these objects are highly variable. The H α  line has multiple, variable emission and absorption components. In these oxygen-rich post-AGB stars atmospheric lines, such as near-infrared Ca ii triplet and low-excitation atomic lines, also have multiple components and sometimes show line doubling, indicative of shocks induced by pulsation.
000003899 536__ $$aGOA/$$c13/$$f012; BR/143/A2/STARLAB
000003899 594__ $$aNO
000003899 6531_ $$a late-stage stellar evolution
000003899 6531_ $$aplanetary nebulae
000003899 6531_ $$amulti-wavelength photometry
000003899 6531_ $$aradial velocity
000003899 6531_ $$astellar evolution
000003899 6531_ $$apulsation
000003899 6531_ $$ashock wave
000003899 700__ $$aHrivnak, B. J.
000003899 700__ $$aVan Winckel, H.
000003899 700__ $$aSperauskas, J.
000003899 700__ $$aBohlender, D.
000003899 773__ $$c131-135$$n4$$pGalaxies$$v6$$y2018
000003899 8560_ $$fgriet.vandesteene@observatoire.be
000003899 85642 $$ahttps://www.mdpi.com/2075-4434/6/4/131/htm
000003899 8564_ $$s1137069$$uhttp://publi2-as.oma.be/record/3899/files/postAGB_galaxies-06-00131.pdf
000003899 8564_ $$s4319$$uhttp://publi2-as.oma.be/record/3899/files/postAGB_galaxies-06-00131.gif?subformat=icon$$xicon
000003899 8564_ $$s4595$$uhttp://publi2-as.oma.be/record/3899/files/postAGB_galaxies-06-00131.jpg?subformat=icon-180$$xicon-180
000003899 905__ $$apublished in
000003899 980__ $$aREFERD