Publication Date:
2011-09-16
Description:
Delta Scuti (deltaSct) stars are opacity-driven pulsators with masses of 1.5-2.5 Mmiddle dot in circle, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy through the outer 30 per cent of the star and excites a rich spectrum of resonant acoustic modes. Based on the solar example, with no firm theoretical basis, models predict that the convective envelope in deltaSct stars extends only about 1 per cent of the radius, but with sufficient energy to excite solar-like oscillations. This was not observed before the Kepler mission, so the presence of a convective envelope in the models has been questioned. Here we report the detection of solar-like oscillations in the deltaSct star HD187547, implying that surface convection operates efficiently in stars about twice as massive as the Sun, as the ad hoc models predicted.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Antoci, V -- Handler, G -- Campante, T L -- Thygesen, A O -- Moya, A -- Kallinger, T -- Stello, D -- Grigahcene, A -- Kjeldsen, H -- Bedding, T R -- Luftinger, T -- Christensen-Dalsgaard, J -- Catanzaro, G -- Frasca, A -- De Cat, P -- Uytterhoeven, K -- Bruntt, H -- Houdek, G -- Kurtz, D W -- Lenz, P -- Kaiser, A -- Van Cleve, J -- Allen, C -- Clarke, B D -- England -- Nature. 2011 Sep 29;477(7366):570-3. doi: 10.1038/nature10389.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Astronomy, University of Vienna, Turkenschanzstrasse 18, A-1180 Vienna, Austria. victoria.antoci@univie.ac.at〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/21918514" target="_blank"〉PubMed〈/a〉
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
