Measurements of Solar Irradiance and Effective Temperature as a Probe of Solar Interior Magnetic Fields
Measurements of Solar Irradiance and Effective Temperature as a Probe of Solar Interior Magnetic Fields
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DOI：
10.1086/319470
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发表时间：
2000-07
期刊：
影响因子：
--
通讯作者：
L. Li;S. Sofia
中科院分区：
文献类型：
--
作者：
L. Li;S. Sofia
We argue that a variety of solar data suggest that the activity-cycle timescale variability of the total irradiance is produced by structural adjustments of the solar interior. Assuming these adjustments are induced by variations of internal magnetic fields, we use measurements of the total irradiance and effective temperature over the period from 1978 to 1992 to infer the magnitude and location of the magnetic field. Using an updated stellar evolution model, which includes magnetic fields, we find that the observations can be explained by fields with peak values ranging from 120 to 2.3 kG, located in the convection zone between 0.959 and 0.997 R☉, respectively. The corresponding maximal radius changes are 17 km when the magnetic field is located at 0.959 R☉ and 3 km when it is located at 0.997 R☉. At these depths, the W-parameter (defined by Δ ln R/Δ ln L, where R and L are the radius and luminosity) ranges from 0.02 to 0.006. All these predictions are consistent with helioseismology and recent measurements carried out by the Michelson Doppler Imager experiment on the Solar and Heliospheric Observatory.
