Bibcode
Provencal, J. L.; Montgomery, M. H.; Kanaan, A.; Thompson, S. E.; Dalessio, J.; Shipman, H. L.; Childers, D.; Clemens, J. C.; Rosen, R.; Henrique, P.; Bischoff-Kim, A.; Strickland, W.; Chandler, D.; Walter, B.; Watson, T. K.; Castanheira, B.; Wang, S.; Handler, G.; Wood, M.; Vennes, S.; Nemeth, P.; Kepler, S. O.; Reed, M.; Nitta, A.; Kleinman, S. J.; Brown, T.; Kim, S.-L.; Sullivan, D.; Chen, W. P.; Yang, M.; Shih, C. Y.; Jiang, X. J.; Sergeev, A. V.; Maksim, A.; Janulis, R.; Baliyan, K. S.; Vats, H. O.; Zola, S.; Baran, A.; Winiarski, M.; Ogloza, W.; Paparo, M.; Bognar, Z.; Papics, P.; Kilkenny, D.; Sefako, R.; Buckley, D.; Loaring, N.; Kniazev, A.; Silvotti, R.; Galleti, S.; Nagel, T.; Vauclair, G.; Dolez, N.; Fremy, J. R.; Perez, J.; Almenara, J. M.; Fraga, L.
Bibliographical reference
The Astrophysical Journal, Volume 751, Issue 2, article id. 91 (2012).
Advertised on:
6
2012
Journal
Citations
40
Refereed citations
31
Description
We report on an analysis of 308.3 hr of high-speed photometry targeting
the pulsating DA white dwarf EC14012-1446. The data were acquired with
the Whole Earth Telescope during the 2008 international observing run
XCOV26. The Fourier transform of the light curve contains 19 independent
frequencies and numerous combination frequencies. The dominant peaks are
1633.907, 1887.404, and 2504.897 μHz. Our analysis of the combination
amplitudes reveals that the parent frequencies are consistent with modes
of spherical degree l = 1. The combination amplitudes also provide m
identifications for the largest amplitude parent frequencies. Our
seismology analysis, which includes 2004-2007 archival data, confirms
these identifications, provides constraints on additional frequencies,
and finds an average period spacing of 41 s. Building on this
foundation, we present nonlinear fits to high signal-to-noise light
curves from the SOAR 4.1 m, McDonald 2.1 m, and KPNO 2 m telescopes. The
fits indicate a time-averaged convective response timescale of
τ0 = 99.4 ± 17 s, a temperature exponent N = 85
± 6.2, and an inclination angle of θ i =
32fdg9 ± 3fdg2. We present our current empirical map of the
convective response timescale across the DA instability strip.
Based on observations obtained at the Southern Astrophysical Research
(SOAR) telescope, which is a joint project of the Ministério da
Ciência, Tecnologia, e Inovação (MCTI) da
República Federativa do Brasil, the U.S. National Optical
Astronomy Observatory (NOAO), the University of North Carolina at Chapel
Hill (UNC), and Michigan State University (MSU).
Related projects
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur