| Name: | SMRUTI SASWATA HOTA |
| Affiliation: | PONDICHERRY UNIVERSITY |
| Conference ID: | ASI2025_615 |
| Title: | Transient nature study of classical Be stars using Hα variability |
| Authors: | Smruti Saswata Hota 1, Gourav Banerjee 2 |
| Authors Affiliation: | 1 Smruti Saswata Hota (Pondicherry University, Puducherry - 605014, India)
2 Gourav Banerjee (Indian Institute of Astrophysics, Bangalore - 560034, India) |
| Mode of Presentation: | Poster |
| Abstract Category: | Stars, Interstellar Medium, and Astrochemistry in Milky Way |
| Abstract: | Study of classical Be (Be) stars provide a unique opportunity to investigate circumstellar discs since their spectra display emission lines of different elements that originate from the surrounding gaseous, equatorial discs of these massive main-sequence B-type stars. A distinctive property of almost all Be stars is variability in their emission line profiles. In extreme cases this leads to the complete loss of their discs, thereby giving such stars an appearance of a normal standard B-type star. This ‘transient nature’ of certain Be stars can be tracked through continuous monitoring of their Hα line profile variability. The existing literature shows that any acceptable consensus regarding the disc formation and dissipation timescales for Be stars has not arrived yet. So Banerjee et al. (2022) performed such a study for 9 transient Be stars and further extended the study to start a continuous monitoring program of a larger sample of such Be stars using the 1-m CZT facility at VBO, Kavalur. In this work, I performed thorough literature survey to identify more such interesting Be stars that have shown transient nature at least once in their lifetime taking data from Barnsley & Steele (2013) who presented the Hα line profile variability for 55 Northern Be stars. Looking through existing literature, we identified 19 among these 55 stars have shown transient nature in the past at least once, thus increasing the sample size of the present monitoring program considerably. Our study also detected that while one star HD 170682 might have shown a disc loss and formation episode within around two years during 1998 to 2000, another star, HD 171406 might have passed through a cycle of disc-loss to disc formation followed by again disc dissipation episodes within a timescale of two decades from 1998 to 2020.
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