Non-equidistant spectrum of gravity modes of a solar model with a mixed core

Solar Physics ◽  
1990 ◽  
Vol 128 (1) ◽  
pp. 111-122 ◽  
Author(s):  
J. Provost ◽  
G. Berthomieu ◽  
E. Gavryuseva ◽  
V. Gavryusev
2008 ◽  
Vol 17 (10) ◽  
pp. 2106-2109 ◽  
Author(s):  
AKIHIRO TOHSAKI

A nucleon is available for examining the property of α-condensate, which consists of composite bosons. Only a microscopic model, which fully takes into account the Pauli principle between all the constituent nucleons, can play its role. We give numerical results by equidistant spectrum model for the system of a neutron and 3α-cluster states. We discuss whether an extra nucleon can exist in the center of α-condensate or not.


2014 ◽  
Vol 10 (S305) ◽  
pp. 381-386
Author(s):  
H. D. Supriya ◽  
H. N. Smitha ◽  
K. N. Nagendra ◽  
J. O. Stenflo ◽  
M. Bianda ◽  
...  

AbstractThe Ca i 4227 Å is a chromospheric line exhibiting the largest degree of linear polarization near the limb, in the visible spectrum of the Sun. Modeling the observations of the center-to-limb variations (CLV) of different lines in the Second Solar Spectrum helps to sample the height dependence of the magnetic field, as the observations made at different lines of sight sample different heights in the solar atmosphere. Supriya et al. (2014) attempted to simultaneously model the CLV of the (I, Q/I) spectra of the Ca i 4227 Å line using the standard 1-D FAL model atmospheres. They found that the standard FAL model atmospheres and also any appropriate combination of them, fail to simultaneously fit the observed Stokes (I, Q/I) profiles at all the limb distances (μ) satisfying at the same time all the observational constraints. This failure of 1-D modeling approach can probably be overcome by using multi-dimensional modeling which is computationally expensive. To eliminate an even wider choice of 1-D models, we attempt here to simultaneously model the CLV of the (I, Q/I) spectra using the FCHHT solar model atmospheres which are updated and recent versions of the FAL models. The details of our modeling efforts and the results are presented.


1980 ◽  
Vol 5 ◽  
pp. 441-444
Author(s):  
M. Gabriel

In this review we discuss the problems raised by the discovery that the sun was, in the past, unstable towards non-radial oscillations.In 1972, Fowler (1972), in an attempt to explain the low-neutrino flux measured in Davis’ experiment (now 1.6 snu, while the standard solar model predicts 4.4 snu) suggested that the sun could have undergone, some 10 years ago, a change in structure because of sudden mixing of the inner core. During the same year Dilke and Gough (1972) suggested the sun is unstable to low-order gravity modes (g+ modes) of non-radial oscillation and that the mixing is triggered when the amplitude of the oscillation becomes large enough.


2014 ◽  
Vol 782 (2) ◽  
pp. 81 ◽  
Author(s):  
B. van der Holst ◽  
I. V. Sokolov ◽  
X. Meng ◽  
M. Jin ◽  
W. B. Manchester, IV ◽  
...  

2018 ◽  
Vol 481 (1) ◽  
pp. L35-L39 ◽  
Author(s):  
Andreas Christ Sølvsten Jørgensen ◽  
Jakob Rørsted Mosumgaard ◽  
Achim Weiss ◽  
Víctor Silva Aguirre ◽  
Jørgen Christensen-Dalsgaard

1993 ◽  
Vol 137 ◽  
pp. 535-537 ◽  
Author(s):  
I.W. Roxburgh ◽  
S.V. Vorontsov

AbstractWe extend the second-order asymptotic description developed by Tassoul (1980, 1990) to the forth order, taking into account both gravity perturbations and realistic (non-polytropic) structure of the stellar envelope. We examine the accuracy of the asymptotic description by the direct computations for a solar model.


1990 ◽  
Vol 121 ◽  
pp. 179-186 ◽  
Author(s):  
K. S. Hirata ◽  
T. Kajita ◽  
T. Kifune ◽  
K. Kihara ◽  
M. Nakahata ◽  
...  

AbstractThe observation of 8B solar Neutrinos in the Kamiokande-II detector is presented. Based on 450 days of data in the time period of January 1987 through May 1988, the measured flux obtained with Ee ≥ 9.3 MeV was 0.46 ± 0.13 (stat) ± 0.08 (sys) of the value predicted by the standard solar model. The detector and analysis methods were improved since June 1988 and the background level has been decreased by a factor of about three since then.


1988 ◽  
Vol 123 ◽  
pp. 121-124
Author(s):  
Gabrielle Berthomieu ◽  
Janine Provost

Asymptotic properties of low degree gravity modes and their relation to the stratification of the model through the Brunt-Väissälä frequency are discussed for a solar type model and for a 10 M⊙ model. For the solar model, taking into account the quasiadiabaticity of the solar convection zone, it is shown that two global constraints on the deep interior of the solar model can be derived from a set of g-modes periods in the observed range. However modes with large periods, i.e. larger than those up to now observed, are required to obtain informations on the stratification just below the convection zone. For the 10 M⊙ model, the preliminary results show that the existence of a layer with a large mean molecular weight gradient destroys the equidistance of the periods of gravity modes of a given degree and that some informations on the properties of this layer can be obtained from the analysis of the g-modes periods.


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