Recurrent Novae — A Review

K Mukai

doi:10.14311/app.2015.02.0246

Abstract

In recent years, recurrent nova eruptions are often observed very intensely in wide range of wavelengths from radio to optical to X-rays. Here I present selected highlights from recent multi-wavelength observations. The enigma of T Pyx is at the heart of this paper. While our current understanding of CV and symbiotic star evolution can explain why certain subset of recurrent novae have high accretion rate, that of T Pyx must be greatly elevated compared to the evolutionary mean. At the same time, we have extensive data to be able to estimate how the nova envelope was ejected in T Pyx, and it turns to be a rather complex tale. One suspects that envelope ejection in recurrent and classical novae in general is more complicated than the textbook descriptions. At the end of the review, I will speculate that these two may be connected.

Highlights

Nova eruptions are understood to be powered by thermonuclear runaway (TNR) on the surface of accreting white dwarfs
Because the recurrent nature of these objects allows studies that one cannot undertake for classical novae (CNe), Recurrent novae (RNe) have become the subject of intensive study
It is expected that RNe harbor massive white dwarfs accreting at a very high rate

Summary

Introduction

Nova eruptions are understood to be powered by thermonuclear runaway (TNR) on the surface of accreting white dwarfs. Hundreds of objects in the Galaxy have been seen to experience one nova eruption: these are called classical novae (CNe). Recurrent novae (RNe) are objects that have been seen to experience multiple nova eruptions. We expect RNe to contain near Chandrasekhar mass white dwarf accreting at a high rate. This makes RNe candidate progenitors of Type Ia supernova. For this reason, and because the recurrent nature of these objects allows studies that one cannot undertake for CNe, RNe have become the subject of intensive study

Results

Discussion

Conclusion