Long term UBV RI photometric and spectral monitoring of nova KT Eri during 2009-2023

TL;DR

This paper reports a long-term observational study of nova KT Eri from 2009 to 2023, focusing on its photometric and spectral variability during quiescence, revealing complex multi-periodic and chaotic activity patterns.

Contribution

It provides the first extensive long-term UBV RI photometric and spectral dataset of KT Eri, highlighting its high excitation conditions and complex variability patterns in quiescence.

Findings

High excitation conditions with dominant HeII 4686 emission line.

Complex multi-periodic and chaotic photometric variability.

No significant change in mean color and brightness before and after outburst.

Abstract

We present a status report of our intensive and long-term UBV RI photometric monitoring of nova KT Eri since its outbust in 2009. The old-nova in quiescence is characterized by very high excitation conditions (HeII 4686 being constantly the strongest emission line in optical spectra) and a complex-pattern photometric variability of one mag amplitude in which multi-periodicities (from hours to years) are mixed with chaotic activity of similar amplitude. Mean color and brightness levels are the same for pre- and post- outburst quiescence.