Researchers from the Yunnan Observatories of the Chinese language Academy of Sciences (CAS) have performed an in depth asteroseismic evaluation on an especially low-mass white dwarf (WD) that reveals suspected strain mode (p-mode) pulsations. They not solely detect the abundance profiles contained in the WD, but additionally present theoretical assist for the fact of the p-modes.
The research was revealed in The Astrophysical Journal.
Some WDs have been discovered to exhibit pulsations. One kind of pulsation is the p-mode with excessive frequency, and the opposite is the gravity mode (g-mode) with low frequency.
The intervals of p-mode pulsations are often within the order of seconds or much less on WDs, which makes it a problem to detect these pulsations. Nonetheless, for low-mass WDs, the intervals of p-mode pulsations may be so long as 100 seconds and has an observable amplitude.
SDSS J111215.82+111745.0 is an especially low-mass WD. Two shortperiod pulsations, 107.56 seconds and 134.275 seconds, had been detected on this star. If the fact of those two suspected p-mode pulsations is confirmed, they’d be the primary p-mode pulsations noticed on a WD.
On this research, the researchers tried to supply sturdy assist for the affirmation of those suspected p-mode pulsations by way of modeling and evaluation.
They made an in depth asteroseismic modeling for SDSS J111215.82+111745.0, wherein the hydrogen abundance profile was taken as a variable. They took the entire set of seven pulsating intervals (two p-modes and 5 g-modes) under consideration and fitted them with the fashions’ eigenfrequencies.
The 2 suspected p-modes had been effectively represented within the best-fit mannequin. They’ve discovered a mannequin with p-mode pulsations per the intervals noticed on SDSS J111215.82+111745.0, which gives theoretical assist for the fact of the 2 p-mode pulsations.
Furthermore, the principle parameters, M = 0.1650 ± 0.0137 solar mass and Teff = 9750 ± 560 Ok, and the chemical profiles of this star had been decided from the best-fit mannequin.
The stellar parameters decided from their mannequin had been in good settlement with that derived from spectroscopy and with the outcomes of different asteroseismic evaluation.
Extra info:
Jie Su et al, Asteroseismology of the Pulsating Extraordinarily Low-mass White Dwarf SDSS J111215.82 + 111745.0: A Mannequin with p-mode Pulsations Per the Observations, The Astrophysical Journal (2023). DOI: 10.3847/1538-4357/aca533
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Chinese Academy of Sciences
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Theoretical assist for actuality of strain mode pulsations on a white dwarf (2023, February 24)
retrieved 24 February 2023
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