Delta Scuti Network observations of XX Pyx: Detection of 22 pulsation modes and of short-term amplitude and frequency variations
- Author(s)
- Gerald Handler, T Arentoft, R R Shobbrook, Matt A. Wood, Lisa A. Crause, P Crake, F Podmore, A Habanyama, T Oswalt, Peter V. Birch, G Lowe, Christiaan Sterken, P Meintjes, J Brink, Carmen Claver, R Medupe, Joyce Ann Guzik, T E Beach, Peter Martinez, Elia M. Leibowitz, P. A. Ibbetson, T. Smith, B N Ashoka, N E Raj, Luis A. Balona, Darragh O'Donoghue, J E S Costa, Michel Breger
- Abstract
We report multisite observations devoted to the main-sequence δ Scuti star XX Pyx, conducted as the 17th run of the Delta Scuti Network. Over 125 nights a total of 550 h of usable time-series photometric B- and V-filter data were acquired involving both photoelectric and CCD measurements at eight observatories spread around the world, which represents the most extensive single time-series for any pulsating star other than the Sun obtained so far. We describe our observations and reduction methods, and present the frequency analysis of our new data. First, we detect six new pulsation and five new combination frequencies in the star's light curves. We also discover evidence for amplitude and/or frequency variations of some of the modes during the observations. These can occur on time-scales as short as 20 d and show quite diverse behaviour. To take them into account in the frequency analysis, a so-called non-linear frequency analysis method was developed, allowing us to quantify the temporal variability of the modes and to compensate for it. Following that we continue the frequency search and we also incorporate published multisite observations. In this way, we reveal three more pulsation and two more combination frequencies. In the end, we report a total of 30 significant frequencies - 22 of which correspond to independent pulsation modes. This is the largest number of independent modes ever detected in the light curves of a δ Scuti star.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- The University of Sydney, Australian National University, Florida Institute of Technology, University of Cape Town, Perth Observatory, University of Simbabwe, University of Zambia, Vrije Universiteit Brussel, University of the Free State, Universitat Rovira i Virgili, South African Astronomical Observatory (SAAO), Los Alamos National Laboratory, University of Texas, Austin, Tel Aviv University, Indian Space Research Organization, Universidade Federal do Rio Grande do Sul
- Journal
- Monthly Notices of the Royal Astronomical Society
- Volume
- 318
- Pages
- 511-525
- No. of pages
- 15
- ISSN
- 0035-8711
- Publication date
- 2000
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/aed83b4d-3111-4b16-812d-7a2b67e0a50c