2024/07/25 by Jae Woo Lee, Kyeongsoo Hong, Lee, Jae Woo +5 · 1 citation
Physics and Astronomy · Biochemistry, Genetics and Molecular Biology · Engineering · #Scientific Research and Discoveries #Geomagnetism and Paleomagnetism Studies #Magnetic Bearings and Levitation Dynamics
paper · pdf · doi:10.48550/arxiv.2407.17729
VLT/UVES spectroscopic and TESS photometric observations for WASP 0346-21 allow the direct determination of its physical properties, along with the detection of a circumbinary object and oscillating signals. The high-resolution spectra yielded the radial velocities of all three stars and the atmospheric parameters of T\rm eff,A = 7225±42 K, [M/H] = 0.30±0.03 dex, and v\rm Asin i = 78±5 km s-1 of the primary component. The combined analysis of these observations resulted in the fundamental parameters of the eclipsing components and the third light of l3 = 0.043±0.004, which is consistent with the light contribution of the tertiary star observed in the echelle spectra. WASP 0346-21 A resides within the overlapping main-sequence domain of δ Sct and γ Dor variables, while the secondary component of M\rm B = 0.185±0.013 M_\odot, R\rm B = 0.308±0.023 R_\odot, T\rm eff,B = 10,655±146 K, and L\rm B = 1.09±0.17 L_\odot matches well with the low-mass white dwarf (WD) model for Z = 0.01, corresponding to the thick-disk population classified by the Galactic kinematics. Multifrequency analyses were performed on the residual TESS data after removing the binarity effects. The low frequencies around 26.348 day-1 and 17.683 day-1 are δ Sct pulsations originating from WASP 0346-21 A, and the high frequencies of 97.996 day-1 and 90.460 day-1 are considered to be extremely low-mass WD oscillations. These results demonstrate that WASP 0346-21 is a hierarchical triple system, consisting of an EL CVn binary with multiperiodic pulsations in each component and a distant outer tertiary.