von Hippel, T;
Farihi, J;
Provencal, JL;
Kleinman, SJ;
Pringle, JE;
Swan, A;
Fontaine, G;
... Zola, S; + view all
(2024)
The Morphology of the Asteroidal Dust around White Dwarf Stars: Optical and Near-infrared Pulsations in G29-38.
Astrophysical Journal
, 963
(2)
p. 113.
10.3847/1538-4357/ad1bd0.
Preview |
PDF
von_Hippel_2024_ApJ_963_113.pdf - Published Version Download (1MB) | Preview |
Abstract
More than 36 yr have passed since the discovery of the infrared excess from circumstellar dust orbiting the white dwarf G29-38, which at 17.5 pc it is the nearest and brightest of its class. The precise morphology of the orbiting dust remains only marginally constrained by existing data, subject to model-dependent inferences, and thus fundamental questions of its dynamical origin and evolution persist. This study presents a means to constrain the geometric distribution of the emitting dust using stellar pulsations measured at optical wavelengths as a variable illumination source of the dust, which reradiates primarily in the infrared. By combining optical photometry from the Whole Earth Telescope with 0.7-2.5 μm spectroscopy obtained with SpeX at NASA’s Infrared Telescope Facility, we detect luminosity variations at all observed wavelengths, with variations at most wavelengths corresponding to the behavior of the pulsating stellar photosphere, but toward the longest wavelengths the light curves probe the corresponding time variability of the circumstellar dust. In addition to developing methodology, we find the pulsation amplitudes decrease with increasing wavelength for principal pulsation modes, yet increase beyond ≈2 μm for nonlinear combination frequencies. We interpret these results as combination modes derived from the principal modes of identical ℓ values and discuss the implications for the morphology of the warm dust. We also draw attention to some discrepancies between our findings and theoretical expectations for the results of the nonlinearity imposed by the surface convection zone on mode-mode interactions and on the behavior of the first harmonic of the highest-amplitude pulsation mode.
| Type: | Article |
|---|---|
| Title: | The Morphology of the Asteroidal Dust around White Dwarf Stars: Optical and Near-infrared Pulsations in G29-38 |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/1538-4357/ad1bd0 |
| Publisher version: | http://dx.doi.org/10.3847/1538-4357/ad1bd0 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third-party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10190112 |
Archive Staff Only
 |
View Item |
