Zeeman Observations of W Sgr*
نویسندگان
چکیده
A new precise method for measuring magnetic fields on Zeeman plates of the southern cepheid W Sgr is reviewed. Ten plates over the 7_6 period of pulsation show two extrema in the measured values of the effective magnetic field. The method has a precision of ±0.4_ in the Zeeman shift corresponding to ±50 gauss (g). A negative "spike" of -220g occurred at the time of arrival of the compressional wave of pulsation at the stellar surface. A positive field of +270g occurred at the phase of most rapid contraction near the temperature minimum of the pulsation cycle.
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تاریخ انتشار 2010