Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions
- Author(s)
- Mike D. Reed, Steven D. Kawaler, S Zola, Xianjun J. Jiang, Stefan Dreizler, S L Schuh, Jochen Lennart Deetjen, Romualdas Kalytis, E G Meistas, R Janulis, D Alisauskas, J Krzesinski, M Vuckovic, Pawel A. Moskalik, W Ogloza, A Baran, Greg Stachowski, J M Gonzalez Perez, Anjum S. Mukadam, Todd K. Watson, Chris Koen, Paul A. Bradley, Margarida S. Cunha, M Kilic, Eric W. Klumpe, Robert F. Carlton, Gerald Handler, D Kilkenny, Reed L. Riddle, Noel Dolez, G Vauclair, M Chevreton, Matt A. Wood, Albert D. Grauer, Gordon E. Bromage, Jan Erik Solheim, Roy H. Ostensen, Ana Ulla, Matthew R. Burleigh, S. A. Good, O Hürkal, R F Anderson, Erika Pakstiene
- Abstract
Since pulsating subdwarf B (sdBV or EC14026) stars were first discovered, observational efforts have tried to realize their potential for constraining the interior physics of extreme horizontal branch stars. Difficulties encountered along the way include uncertain mode identifications and a lack of stable pulsation mode properties. Here we report on Feige 48, an sdBV star for which follow-up observations have been obtained spanning more than four years. These observations show some stable pulsation modes. We resolve the temporal spectrum into five stable pulsation periods in the range 340-380 s with amplitudes less than 1 per cent, and two additional periods that appear in one data set each. The three largest amplitude periodicities are nearly equally spaced, and we explore the consequences of identifying them as a rotationally split l = 1 triplet by consulting a representative stellar model. The general stability of the pulsation amplitudes and phases allows us to use the pulsation phases to constrain the time-scale of evolution for this sdBV star. Additionally, we are able to place interesting limits on any stellar or planetary companion to Feige 48.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Case Western Reserve University, Iowa State University, Pedagogical University of Cracow, Chinese Academy of Sciences (CAS), Eberhard Karls Universität Tübingen, Georg-August-Universität Göttingen, Vilnius University (VU), Apache Point Observatory, Katholieke Universiteit Leuven, Polish Academy of Sciences, University of Tromsø - The Arctic University of Norway, University of Washington, Southwestern University, South African Astronomical Observatory (SAAO), Los Alamos National Laboratory, Universidade do Porto, Kitt Peak National Observatory, University of Texas, Austin, Middle Tennessee State University (MTSU), Laboratoire d’Astrophysique de Toulouse-Tarbes, Observatoire Midi-Pyrénées, Université de recherche Paris Sciences et Lettres, Florida Institute of Technology, University of Arkansas at Little Rock, University of Central Lancashire, University of Oslo, Universidade Federal de Santa Catarina, Enxeñaría Telemática, University of Leicester, EGE University, University of North Carolina at Chapel Hill
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 348
- Pages
- 1164-1174
- No. of pages
- 11
- ISSN
- 0035-8711
- Publication date
- 2005
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/3a63d4b2-82e7-465b-a689-29373fed9920