Babette Bohn. Review of "Defining the Renaissance Virtuosa: Women Artists and the Language of Art History and Criticism" by Fredrika H. Jacobs.

Excitation of transverse magnetic tube waves in stellar convection zones

“…Therefore, the properties of the turbulence occurring on and below the solar surface are usually determined by specifying a turbulent energy spectrum. For the turbulent energy spectrum in the solar atmosphere many different shapes have been proposed (e.g., Stein 1967;Bohn 1984;Goldreich & Kumar 1988, 1990. Musielak et al (1994) have combined some theoretical arguments about the turbulence with the results of numerical simulations (e.g., Cattaneo et al 1991) as well as observational results (e.g., Zahn 1987;Muller et al 1989Muller et al , 1994 and suggested that the spatial and temporal parts of the turbulent energy spectrum can be described by an extended Kolmogorov spectrum with a modified Gaussian frequency factor.…”

“…The solar convection zone model used here to perform our calculations of the generation of transverse tube wave is a modified version of stellar envelope computer code originally used by Bohn (1981Bohn ( , 1984 and later modified by Theurer (1993) and Ulmschneider et al (1996). To run this code, it is required to specify the effective temperature T eff and the surface gravity g. The code employs a mixing-length description of convection, which assumes that the energy-containing eddies have spatial scales comparable to the local pressure scale height H (Prandtl 1925); this means that the so-called mixing-length parameter α = l mix /H, where l mix is the mixing-length, must be of the order of unity.…”

“…As a result, previously calculated stellar acoustic wave energy fluxes (e.g., Renzini et al 1977;Bohn 1981Bohn , 1984 are incorrect. We have corrected the Lighthill-Stein theory by incorporating an improved description of the spatial and temporal spectrum of the turbulent convection and used this corrected theory to calculate new acoustic wave energy spectra and fluxes for late-type stars .…”

Magnetic wave energy fluxes for late-type stars

“…Our recent work has shown that previously calculated stellar acoustic wave energy fluxes (e.g., Bohn 1981Bohn , 1984 are incorrect, mainly because several fundamental assumptions in the LighthillStein theory (Lighthill 1952;Stein 1967) of sound generation turned out to be physically unjustified (Musielak et al 1994). We have corrected the Lighthill-Stein theory by incorporating an improved description of the spatial and temporal spectrum of the turbulent convection and used this corrected theory to calculate new stellar acoustic wave energy fluxes (see Ulmschneider et al 1996 for stars of solar type metal abundances; and Ulmschneider et al 1999, for stars with nonsolar metallicities).…”