scholarly journals Theoretical Review of Secular Instabilities in the Sun

1980 ◽  
Vol 5 ◽  
pp. 441-444
Author(s):  
M. Gabriel
Keyword(s):  
Inner Core ◽  
Neutrino Flux ◽  
Radial Oscillation ◽  
Solar Model ◽  
The Sun ◽  
Standard Solar Model ◽  
The Past ◽  
Low Order

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.

Status of the Soviet-American gallium experiment

1994 ◽  
Vol 346 (1678) ◽  
pp. 15-21
Keyword(s):  
Solar Neutrino ◽  
Neutrino Flux ◽  
Solar Model ◽  
Data Sets ◽  
The Sun ◽  
Standard Solar Model ◽  
Baksan Neutrino Observatory ◽  
A Value ◽  
Solar Neutrino Flux

A radiochemical 71 Ga- 71 Ge experiment to determine the primary flux of neutrinos from the Sun began measurements of the solar neutrino flux at the Baksan Neutrino Observatory in 1990. The number of 71 Ge atoms extracted from 30 tons of gallium in 1990 and from 57 tons of gallium in 1991 was measured in 12 runs during the period of January 1990 to December 1991. The combined 1990 and 1991 data-sets give a value of 58 + 17/ —24 (stat) ± 14 (syst) SNU. This is to be compared with 132 + 7/ —5 SNU predicted by the Standard Solar Model.

SOLAR MODELS: AN HISTORICAL OVERVIEW

2003 ◽  
Vol 18 (22) ◽  
pp. 3761-3776 ◽  
Author(s):  
JOHN N. BAHCALL
Keyword(s):  
Solar Neutrino ◽  
Neutrino Flux ◽  
New Physics ◽  
Solar Model ◽  
Historical Overview ◽  
Standard Solar Model ◽  
Solar Luminosity ◽  
Consensus View ◽  
Neutrino Fluxes ◽  
Neutrino Experiments

I will summarize in four slides the 40 years of development of the standard solar model that is used to predict solar neutrino fluxes and then describe the current uncertainties in the predictions. I will dispel the misconception that the p-p neutrino flux is determined by the solar luminosity and present a related formula that gives, in terms of the p-p and 7 Be neutrino fluxes, the ratio of the rates of the two primary ways of terminating the p-p fusion chain. I will also attempt to explain why it took so long, about three and a half decades, to reach a consensus view that new physics is being learned from solar neutrino experiments. Finally, I close with a personal confession and some personal remarks.

Structure inversions with the VIRGO data

1997 ◽  
Vol 181 ◽  
pp. 159-166 ◽  
Author(s):  
Thierry Appourchaux ◽  
Takashi Sekii ◽  
Douglas Gough ◽  
Umin Lee ◽  
Christoph Wehrli ◽  
...  
Keyword(s):  
Time Series ◽  
Core Structure ◽  
Solar Model ◽  
Data Sets ◽  
The Sun ◽  
Standard Solar Model ◽  
Inversion Procedure ◽  
Good Agreement

The p-mode frequencies obtained by the VIRGO instrument have been inverted to derive the solar core structure. Two sets of frequencies have been used in the inversions. The sets are derived from different time series (the second containing the first), using different procedures for fitting the spectra. The influence of the correlations between the p-mode frequencies has been implemented in the inversion procedure. The two data sets are in good agreement with each other, and show no evidence that the sun is significantly different from the latest available standard solar model.

Introductory remarks

1994 ◽  
Vol 346 (1678) ◽  
pp. 1-2 ◽  
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Neutrino Flux ◽  
The Sun ◽  
Gamma Ray Astronomy ◽  
The Past ◽  
The Subject ◽  
Neutrino Astronomy ◽  
The Universe ◽  
Particle Physicist

Nearly twenty years ago, G. D. Rochester and I organized a Discussion Meeting here on the origin of the cosmic radiation. P art of that meeting was devoted to primary gamma rays, and this meeting was followed a few years later by a meeting devoted entirely to gamma ray astronomy. At that time gamma rays represented a ‘new window on the Universe’. Now it is the turn of neutrinos to move into that slot, although it must be said that neutrino astronomy is not as far on as gamma ray astronomy was at that stage. Nevertheless, the subject has started and has already thrown up some dramatic questions, questions of interest to both astronomer and elementary particle physicist. In the more conventional astronomies, the Sun appears to be quite well behaved, and reasonably understood, with the interests of many centring on more distant and ‘dramatic’ objects, such as supernovae and extragalactic sources. With neutrinos, however, supernovae seem to be well behaved — at the superficial level, at least and based on one event — but the Sun does not. The remarkable deficit in solar neutrino flux recorded by Davis and collaborators over the past decades has been confirmed and we look forward to hearing the details of these confirmations, as well as the energy dependence of the flux and its comparison with expectation.

MEASUREMENT OF 8B SOLAR NEUTRINO FLUX AND ENERGY SPECTRUM AT SUPER-KAMIOKANDE

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 721-723
Author(s):  
GENE GUILLIAN
Keyword(s):  
Energy Spectrum ◽  
Electron Energy ◽  
Solar Neutrino ◽  
Neutrino Flux ◽  
Electron Energy Spectrum ◽  
Solar Model ◽  
Standard Solar Model ◽  
Spectrum Measurement ◽  
Solar Neutrino Flux ◽  
Night Flux

The latest Super-Kamiokande measurement of 8 B solar neutrino flux and recoil electron energy spectrum are presented. The highlights of our results are the day vs night flux asymmetry, which differs from zero at the 1.3 σ level, and the energy spectrum measurement, which shows no significant distortion compared to the BP98 standard solar model.

Theoretical Eigenfrequencies of Solar Oscillations of Low Harmonic Degree l in Five-Minute Range

1983 ◽  
Vol 66 ◽  
pp. 231-232
Author(s):  
H. Shibahashi ◽  
Y. Osaki
Keyword(s):  
Standard Model ◽  
Power Spectra ◽  
Solar Model ◽  
The Sun ◽  
Standard Solar Model ◽  
Harmonic Index ◽  
Normal Composition ◽  
Harmonic Degree ◽  
Slight Discrepancy ◽  
Full Disk

AbstractWe have calculated eigenfrequencies of radial and nonradial p-mode oscillations with low harmonic index l (l = 0, 1, 2, 3, and 4) for a standard solar model with normal composition and appoximately the correct age. It is found that theoretical eigenfrequencies calculated for our standard model agree approximately with observed peaks in the power spectra for the full-disk five minute oscillation of the Sun (Claverie et al., 1980; Grec et al., 1983; Scherrer et al., 1983) in agreement with other recent works (Christensen-Dalsgaard and Gough, 1980; Scuflaire et al., 1981). However, there still remains a slight discrepancy between theory and observations in such a sense that the theoretical eigenfrequencies are slightly lower than observations (see Figure 1).

Perspectives on the Interior of the Sun

2000 ◽  
Vol 179 ◽  
pp. 331-337
Author(s):  
S. M. Chitre
Keyword(s):  
Particle Physics ◽  
Solar Model ◽  
The Sun ◽  
Standard Solar Model ◽  
Physical Conditions ◽  
Viable Solution ◽  
Internal Constitution ◽  
Structure Equations ◽  
Neutrino Fluxes ◽  
Oscillation Frequencies

AbstractThe interior of the Sun is not directly accessible to observations. Nonetheless, it is possible to infer the physical conditions inside the Sun with the help of structure equations governing its equilibrium and with the powerful observational tools provided by the neutrino fluxes and oscillation frequencies. The helioseismic data show that the internal constitution of the Sun can be adequately represented by a standard solar model. It turns out that a cooler solar core is not a viable solution for the measured deficit of neutrino fluxes, and the resolution of the solar neutrino puzzle should be sought in the realm of particle physics.

scholarly journals Report on the Homestake Chlorine Solar Neutrino Experiment

1990 ◽  
Vol 121 ◽  
pp. 171-177 ◽  
Author(s):  
R. Davis ◽  
K. Lande ◽  
C.K. Lee ◽  
B.T. Cleveland ◽  
J. Ullman
Keyword(s):  
Solar Neutrino ◽  
Capture Rate ◽  
Neutrino Flux ◽  
Solar Model ◽  
Neutrino Experiment ◽  
Standard Solar Model ◽  
Solar Neutrino Flux ◽  
Homestake Mine ◽  
Solar Neutrino Experiment

AbstractA report on the results obtained from the chlorine radiochemical solar neutrino experiment in the Homestake mine, Lead, SD. Over the period 1970-1988 a neutrino capture rate of 2.3 ± 0.3 SNU was observed. This rate is discussed in relation: to the theoretical standard solar model, the results from the Kamiokande II experiment, and variations in the solar neutrino flux.

scholarly journals Long periods in diameter, irradiance and activity of the Sun

1988 ◽  
Vol 123 ◽  
pp. 223-226
Author(s):  
Ph. Delache ◽  
F. Laclare ◽  
H. Sadsaoud
Keyword(s):  
Solar Cycle ◽  
Neutrino Flux ◽  
The Sun ◽  
Radio Flux ◽  
Solar Diameter ◽  
The Past ◽  
Total Irradiance

Long periods have been detected in solar diameter measurements obtained during the past 10 years. The same periodicities are also present in other global Sun parameters such as the 10 cm radio flux, the total irradiance, and possibly the neutrino flux. Special attention is paid to periods corresponding to the solar cycle (“C”), 1000 days (“P”) and 320 days (“W”). Studying the respective phases of the signals give some insight to the possible physical origins of these variations.

scholarly journals Asteroseismology of white dwarf stars

1995 ◽  
Vol 10 ◽  
pp. 340-343
Author(s):  
R.E. Nather
Keyword(s):  
White Dwarf ◽  
Neutrino Flux ◽  
Stellar Structure ◽  
Solar Model ◽  
Geological Time ◽  
Standard Solar Model ◽  
Dwarf Stars ◽  
White Dwarf Stars ◽  
Long Time ◽  
Better Than

Perhaps the hardest scientific problems to solve are those most scientists believe have already been solved, but which have not. Any model we make of an astronomical process is doomed to be incomplete at some level; the “broad-brush” picture of stellar structure and evolution is often accepted as a solved problem, but in fact many discrepancies exist between our models and the observations.For example, the “standard solar model” fails to predict the observed neutrino flux from the Sun, and its insistence that the Sun’s luminosity increased by 30% over geological time is not in accord with the evidence. White dwarf stars were thought to be stable against pulsation because the models did not pulsate, and it took a long time to improve them to the point where they did, and could then begin to match our observations of pulsating white dwarfs. For several years their outer hydrogen layers were thought to be extremely thin because models with thicker layers did not pulsate; once the zoning problem was found and solved in the models they could begin to match observations better. These past difficulties illustrate a common danger: it is very easy to confuse our models with the observed reality they try to mimic, and to assume they match better than they do. In what follows I will try to keep the observations and our models of them separate.

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