LONG-TERM PHOTOMETRY OF BE-STARS .1. FADING EVENTS AND VARIATIONS ON TIME SCALES OF YEARS

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dc.contributor.authorMENNICKENT, RE
dc.contributor.authorVOGT, N
dc.contributor.authorSTERKEN, C
dc.date.accessioned2025-01-21T01:35:10Z
dc.date.available2025-01-21T01:35:10Z
dc.date.issued1994
dc.description.abstractStromgren differential uvby photometry of 7 Be stars was analyzed. The data were taken during 1983-1991 by the Long-Term Photometry of Variables team at La Silla. Two low v sin i stars (27 CMa and 28 CMa) showed fading events-that is, sudden fading of a few weeks duration-that were preceded by quasi-periodic oscillations (QPO) on time scales T similar to 10-20 days and amplitudes up to 0.(m)2. In both cases the color variations indicated occurrence of dust ejections. QPO were observed also in 48 Lib and in epsilon Cap, but these were not related to any fading event. Long-term photometric variations up to 0.(m)6 amplitude were seen for all stars. In most cases, these variations were larger in the u band, the stars being bluest when brightest. The Be stars seems to follow a fixed track in the c(1)-(b-y) color plane. The b-y color is not very sensitive to changes in brightness, whereas the c(1) color is strongly correlated with the u magnitude. Moreover, the largest cl changes, compared with u changes, occurred in high v sin i Be stars with shell characteristics. Additional variations on time scales of days were always present; these were larger in the u band. HR 3237 shows peculiar photometric variations, being the exception to the behaviour above described. The amplitudes of short-term and long-term variations of 13 Be stars are correlated; the tightest correlation was found in the y band. We discuss long-term photometric variations and quasi-periodic oscillations as due to enhanced mass loss episodes preceded by global one-armed thin-disk oscillations, which could be excited by some type of photospheric activity.
dc.fuente.origenWOS
dc.identifier.issn0365-0138
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/97649
dc.identifier.wosidWOS:A1994PQ72400016
dc.issue.numero1
dc.language.isoen
dc.pagina.final250
dc.pagina.inicio237
dc.revistaAstronomy & astrophysics supplement series
dc.rightsacceso restringido
dc.subjectSTARS, EMISSION-LINE, BE
dc.subjectSTARS, MASS LOSS
dc.subjectSTARS, VARIABLE
dc.titleLONG-TERM PHOTOMETRY OF BE-STARS .1. FADING EVENTS AND VARIATIONS ON TIME SCALES OF YEARS
dc.typeartículo
dc.volumen108
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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