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Paper: High Sensitivity Observations and Detailed Asteroseismological Analysis of the EC14026 Star Feige 48
Volume: 334, 14th European Workshop on White Dwarfs
Page: 524
Authors: Charpinet, S.; Fontaine, G.; Brassard, P.; Billeres, M.; Green, E.M.; Chayer, P.
Abstract: We present a detailed asteroseismic analysis of the rapidly pulsating sdB star – or EC14026 star – Feige 48 based on data obtained with the Montréal 3-channel fast photometer LAPOUNE attached at the Canada-France-Hawaii 3.6 m telescope. Located near the red edge of the EC14026 instability domain, Feige 48 provides us with less independent modes to constrain its structure through asteroseismological means than other rapidly pulsating sdB stars analyzed so far. Nonetheless, combining various sources of Teff and log g spectroscopic determinations and perfoming an objective search in the parameter space domain allowed us to identify a family of models that can simultaneously best fit the periods while being fully consistent with all spectroscopic measurements. In addition, the fine structure in the period spectrum allows us to derive the rotation period of Feige 48. Other fundamental parameters that follow from our asteroseismic analysis are the surface gravity (to a much higher accuracy than provided by spectroscopy), the total mass of the star, the mass of its H-rich envelope, its radius, total luminosity, absolute magnitude in the V band, as well as its distance from the Earth.
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