Multiperiodic Pulsations of the Unique DAQ White Dwarf J0551+4135: Insights into a Merger Remnant
Year: 2025
Type: article
Abstract: 2MASS J05513444+4135297 (hereafter J0551+4135) is the only pulsating DAQ white dwarf (WD) known with a carbon and hydrogen atmosphere. Its unusual atmospheric composition and kinematics indicate a WD merger origin. We present time-series photometry of J0551+4135 obtained using the Apache Point Observatory 3.5 m, Gemini North 8 m, and Gran Telescopio Canarias 10 m telescopes. J0551+4135 exhibits variations in pulsation amplitude and frequency over time. We detect 10 significant recurring peaks across different subsets of observations, with frequencies ranging from 987 to 1180 μ Hz, consistent with nonradial gravity ( g )-mode oscillations. We present new evolutionary models suitable for spectroscopic characterization of DAQ WDs, and derive a mass of 1.13 ± 0.01 M ⊙ and a cooling age of 1.7 ± 0.1 Gyr for a CO core, and 1.12 ± 0.01 M ⊙ and 1.6 ± 0.1 Gyr for an ONe-core WD, respectively. However, detailed asteroseismology of this unique pulsator has to wait until fully consistent DAQ evolutionary models are available. Further observations, including multisite campaigns to reduce daily aliasing and to improve the signal-to-noise ratio, would be helpful for the identification of additional modes and constraining the internal structure of this unique pulsator.
Source: The Astrophysical Journal
Institutions: KU Leuven, University of Oklahoma, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Astrofísica de La Plata, Universidad Nacional de La Plata, University of Florida, Institut d'Estudis Espacials de Catalunya, Universitat Politècnica de Catalunya, Universität Hamburg, Université de Montréal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, European Commission, Generalitat de Catalunya, Consejo Nacional de Investigaciones Científicas y Técnicas, Fonds Wetenschappelijk Onderzoek, Korea Astronomy and Space Science Institute, Ministério da Ciência, Tecnologia, Inovações e Comunicações, Agencia Nacional de Investigación y Desarrollo, Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación, Instituto de Astrofísica de Canarias, Agència de Gestió d'Ajuts Universitaris i de Recerca, Agencia Estatal de Investigación
Awards: G1060464874, G1346039320, G1627983296, G1693568110, G1873655850, G1925418406, G2038104832, G2064873908, G2355262757, G2462415295, G2784565934, G288263039, G2885007262, G3005324705, G3209474443, G3546882995, G3783830067, G4008337681, G4065279323, G4359570771, G4722035522, G4904803727, G4919915994, G5195188938, G5794478486, G5852091828, G5956904458, G672208782, Current Challenges in the Physics of White Dwarfs: the Origins of the Ultramassive White Dwarf population, G69051668, G7649896884, Characterization of evolved planetary systems around pulsating white dwarfs
OpenAlex ID: W4417145791