Sensitivity of Solar gModes to Varying G Cosmologies
Abstract
The sensitivity of the solar gmode oscillation spectrum to variability in the universal gravitational constant G is described. Solar models in varying G cosmologies were constructed by evolving a zeroage mainsequence stellar model to the Sun's current age, while allowing the value of G to change according to the power law G(t) proportional to t^{beta}, where Beta approximately equals delta G/GH and H is the Hubble constant. All solar models were constrained to the observed luminosity and radius at the current age of the Sun by adjusting the helium abundance and the mixinglength parameter of the models in the usual way for standard stellar models. Lowl gmode oscillation periods were calculated for each of the models and compared to the claimed observation of the solar gmode oscillation spectrum by Hill & Gu (1990). If one accepts Hill & Gu's claims, then within the uncertainties of the physics of the solar model calculation, our models rule out all but (delta G/GH) less than approximately 0.05. In other words, we conclude that G could not have varied by more than 2% over the past 4.5 Gyr, the lifetime of the presentday Sun. This result lends independent support to the validity of the standard solar model.
 Publication:

The Astrophysical Journal
 Pub Date:
 May 1995
 DOI:
 10.1086/175680
 Bibcode:
 1995ApJ...445..148G
 Keywords:

 Abundance;
 Cosmology;
 Gravitation Theory;
 Gravitational Constant;
 Solar Oscillations;
 Stellar Evolution;
 Variability;
 Gravitational Fields;
 Nuclear Reactions;
 Stellar Composition;
 Stellar Luminosity;
 Stellar Models;
 Stellar Temperature;
 Astrophysics;
 COSMOLOGY: THEORY;
 GRAVITATION;
 SUN: OSCILLATIONS