Emission activity of the Be star 60 Cygni

TL;DR

This study analyzes the long-term spectroscopic behavior of the Be star 60 Cygni, revealing disk formation and dissipation patterns, V/R variation, and emission activity over 24 years using observational data.

Contribution

It provides a detailed long-term analysis of 60 Cygni's emission activity and disk evolution, highlighting differences in formation and extinction timescales.

Findings

Disk formed twice between 1992-2016 with stronger emission in the second cycle.

Disk formation takes longer than dissipation, with extinction being steeper.

No clear periodicity observed in V/R variation.

Abstract

In this paper we present results of the spectroscopic analysis of H$\alpha$ line profile of the Be star 60 Cygni. We present time evolution of the equivalent width of the H$\alpha$ line profiles during years 1992 - 2016 and $V/R$ variation during years 1995 - 2016. We analyzed data from Ond\v{r}ejov Observatory and from BeSS Database. The circumstellar disk of the star was present twice during years 1992 - 2016 and the second cycle shows stronger emission activity. We found out that the formation of the disk takes longer time than the disk extinction (extinction is much steeper than the formation) and that there is no evident period of changes in $V/R$ variation.