| Name: | Subharthi Dasgupta |
| Affiliation: | National Institute of Technology Rourkela |
| Conference ID: | ASI2025_170 |
| Title: | On the origin of multiperiodic variability in B-type supergiant Epsilon Ori (HD 37128) |
| Authors: | Subharthi Dasgupta 1, Abhay Pratap Yadav 1 |
| Authors Affiliation: | 1 National Institute of Technology Rourkela, Rourkela-769008, India |
| Mode of Presentation: | Poster |
| Abstract Category: | Stars, Interstellar Medium, and Astrochemistry in Milky Way |
| Abstract: | B-supergiants exhibit significant photometric and spectroscopic variabilities. Their origin is not fully understood but pulsation has been suggested as a possible cause . HD 37128 (Epsilon Orionis) is a very luminous B-type supergiant located in the constellation Orion. The variability of this star has been observed across several wavelengths; however it has been most extensively studied in the optical domain. In several studies, the star has been observed to exhibit line profile variations in both photospheric and wind lines with periods of the order of a few days. In order to understand the origin of these variabilities, we have constructed models of HD 37128 in the mass range of 30 to 70 solar mass and performed non-adiabatic linear stability analysis. Low order radial modes are found to be unstable in the considered models. Mode interactions are present in models having mass below 36 solar mass which is an indication for the presence of strange mode instabilities. From the linear stability analysis, we deduce that the determined periods are consistent with observed periods. Nonlinear numerical simulations in the considered models with mass greater than 50 solar mass lead to finite amplitude pulsations with periods in the range of 1 to 3 days. The presence of multiperiodic variability together with mass-loss in HD 37128 makes it a suitable candidate for asteroseismic analysis and to study the connection between pulsation and mass-loss.
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