Follow-up observations of pulsating subdwarf B stars: Multisite campaigns on PG 1618+563B and PG 0048+091
Diğer yayınlar > Diğer · 2013
Yazarlar: M. D. Reed, S. J. O’toole, D. M. Terndrup, J. R. Eggen, A. -y. Zhou, D. An, C. -w, W. P. Chen, H. -c. Lin, C. Akan, Esin SİPAHİ KILIÇ, H. Worters, D. Kilkenny, S. Zola, Seung-lee Kim, G. A. Gelven, S. L. Harms, G. W. Wolf
Diğer, Uluslararası, 2013,
Özet
We present follow-up observations of pulsating subdwarf B (sdB) stars as part of our efforts to resolve the pulsation spectra for use in asteroseismological analyses. This paper reports on multisite campaigns of the pulsating sdB stars PG 1618+563B and PG 0048+091. Data were obtained from observatories placed around the globe for coverage from all longitudes. For PG 1618+563B, our five-site campaign uncovered a dichotomy of pulsation states: Early during the campaign the amplitudes and phases (and perhaps frequencies) were quite – 2 – variable while data obtained late in the campaign were able to fully resolve five stable pulsation frequencies. For PG 0048+091, our five-site campaign uncovered a plethora of frequencies with short pulsation lifetimes. We find them to have observed properties consistent with stochastically excited oscillations, an unexpected result for subdwarf B stars. We discuss our findings and their impact on subdwarf B asteroseismology.