Tidal mechanism as an impossible cause of the observed secular increase of the astronomical unit

TL;DR

The paper argues that tidal effects cannot explain the observed secular increase in the astronomical unit, challenging recent hypotheses linking tidal interactions to this phenomenon.

Contribution

It provides a theoretical analysis demonstrating that tidal mechanisms are insufficient to account for the observed AU increase.

Findings

Tidal effects are too weak to cause the AU increase.

Angular momentum transfer via tides cannot explain the observed secular change.

Supports the need for alternative explanations for the AU increase.

Abstract

Krasinsky and Brumberg (2004 Celest. Mech. Dyn. Astron., 90, 267) reported a secular increase of the astronomical unit (AU) of 15 meters per century. Recently, Miura et al. (2009, PASJ, 61) proposed that a possible angular momentum transfer from the rotation of the Sun to the orbital motion of the solar system planets may explain the observed increase of the AU. They assumed that the tidal effect between the planets and the Sun is the cause of this transfer. Here we claim that tidal effect cannot be a cause of this type of the transfer to explain the increase of the AU.