On the Periods and Nature of Superhumps

TL;DR

This paper examines the superhump period model, revealing that pressure effects alone do not fully explain observations, indicating the need for further theoretical modifications.

Contribution

It challenges the existing model of superhump periods by demonstrating that pressure effects are insufficient, based on analysis of a larger sample of systems.

Findings

Pressure effects alone cannot explain superhump periods.

Existing models require modifications to incorporate additional factors.

Larger sample analysis refutes previous assumptions.

Abstract

It is commonly accepted that the periods of superhumps can be satisfactorily explained within a model involving apsidal motion of the accretion disk provided the frequency of the apsidal motion in addition to the dynamical term includes also the pressure effects. Using a larger sample of systems with reliable mass ratios it is shown, however, that this view is not true and the model requires further modifications.