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Search for pulsating PMS stars in NGC 6383

K. Zwintz·M. Marconi·P. Reegen·W. W. Weiss
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Abstract

A search for pulsating pre-main sequence (PMS) stars was performed in the young open cluster NGC 6383 using CCD time series photometry in Johnson B & V filters. With an age of only ~1.7 million years all cluster members later than spectral type A0 have not reached the ZAMS yet, hence being ideal candidates for investigating PMS pulsation among A and F type stars. In total 286 stars have been analyzed using classical Fourier techniques. From about a dozen of stars within the boundaries of the classical instability strip, two stars were found to pulsate: NGC 6383 #170, with five frequencies simultaneously, and NGC 6383 #198, with a single frequency. In addition, NGC 6383 #152 is a suspected PMS variable star, but our data remain inconclusive. Linear, non-adiabatic models assuming PMS evolutionary phase and purely radial pulsation were calculated for the two new PMS pulsators. NGC 6383 #170 appears to pulsate radially in third and fifth overtones, while the other three frequencies seem to be of non-radial nature. NGC 6383 #198 pulsates monoperiodically, most probably in the third radial overtone. Magnitudes and B-V colours were available in the literature for only one third of all stars and we used them for calibrating the remaining.

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K. Zwintz, M. Marconi, P. Reegen, W. W. Weiss. 2005-01-12. Search for pulsating PMS stars in NGC 6383. https://doi.org/10.1111/j.1365-2966.2005.08655.x

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