| Abstract : | Massive stars (> 8 Mʘ) evolve to RSGs, BSGs, LBVs, and WRs depending on the parameters like mass, convective overshoot, rotation rates, mixing, mass loss, and metallicity. Hence, stellar evolution varies with different galaxies. M33 galaxy (Z=0.004) is a spiral galaxy in the Local Group which is star resolved and rich in evolved objects. We newly identified six evolved stars in the galaxy M33 through a preliminary survey of the LAMOST emission line stars catalog by Shridharan et al. (2021). This work aims to understand the evolutionary status of those evolved stars using thorough photometric and spectroscopic analysis. The study is a contribution to get more insight into extragalactic stellar evolution. Initial work has been performed by utilizing Gaia DR3 photometry where CMD results confirm all of them to be hot evolved stars and likely to be core helium burning stars with masses approximately between 8 – 40 Mʘ. Further, these results will be compared with theoretical models to have finer details regarding the objects. In the second part of the work, we target optical spectroscopy using LAMOST where all spectra have SNR > 10. We will focus on estimating Teff and L and also, probe prominent line features. A comparison study will be done between the photometric and spectroscopic results. We intend to extend this work for a larger sample and determine the HD limit of this galaxy which has been neglected till today. |
