Year: 2019
Type: article
Abstract: Stars between two and three solar masses rotate rapidly on the main sequence, and the detection of slow core and surface rotation in the core-helium burning phase for these stars places strong constraints on their angular momentum transport and loss. From a detailed asteroseismic study of the mixed-dipole mode pattern in a carefully selected, representative sample of stars, we find that slow core rotation rates in the range reported by prior studies are a general phenomenon and not a selection effect. We show that the core rotation rates of these stars decline strongly with decreasing surface gravity during the core He-burning phase. We argue that this is a model-independent indication of significant rapid angular momentum transport between the cores and envelopes of these stars. We see a significant range in core rotation rates at all surface gravities, with little evidence for a convergence toward a uniform value. We demonstrate using evolutionary models that measured surface rotation periods are a biased tracer of the true surface rotation distribution, and we argue for using stellar models for interpreting the contrast between core and surface rotation rates. The core rotation rates we measure do not have a strong mass or metallicity dependence. We argue that the emerging data strongly favor a model where angular momentum transport is much more efficient during the core He-burning phase than in the shell-burning phases that precede and follow it.
Source: The Astrophysical Journal
Authors: Jamie Tayar, Paul G. Beck, Marc H. Pinsonneault, Rafael A. García, Savita Mathur
Institutions: University of Hawaiʻi at Mānoa, University of Hawaii System, The Ohio State University, University of Graz, Universidad de La Laguna, Nawi Graz, Instituto de Astrofísica de Canarias, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Université Paris-Saclay, Institut de Recherche sur les Lois Fondamentales de l'Univers, Centre National de la Recherche Scientifique, Space Science Institute, Astrophysique, Instrumentation et Modélisation, Sorbonne Paris Cité, Université Paris Diderot
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, Smithsonian Institution, U.S. Department of Energy, National Aeronautics and Space Administration, Alfred P. Sloan Foundation, Yale University, Carnegie Institution of Washington, Vanderbilt University, Ohio State University, University of Utah, University of Washington, Johns Hopkins University, Carnegie Mellon University, University of Notre Dame, University of Portsmouth, New Mexico State University, Space Telescope Science Institute, York University, University of Oxford, Centre National d’Etudes Spatiales, Ministerio de Economía y Competitividad, Ministério da Ciência, Tecnologia e Inovação, Universidad Nacional Autónoma de México, Max-Planck-Institut für Astrophysik, Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Canarias, Office of Science, University of Colorado Boulder, Smithsonian Astrophysical Observatory, Science Mission Directorate, Leibniz-Gemeinschaft, Lawrence Berkeley National Laboratory
Awards: G145748691, G2171960263, G2891798378, Stellar Rotation and the Chronology of the Galaxy, G4182629103, G433322167, G4448586259, G4518818167, G5159282255, G58316358, THE KEPLER MISSION HAS MADE FUNDAMENTAL CONTRIBUTIONS TO OUR KNOWLEDGE OF PLANETS AND STARS. HOWEVER, OUR ABILITY TO UNDERSTAND THE PLANET AND STELLA, G6273510985, G6681768460, G6756316859, G767601387, G7985980831, G8210229802, G8934477357
OpenAlex ID: W2987562834