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In this study, we identified and characterized the hot and luminous UV-brightstars in the globular cluster NGC 2808. We combined data from the Ultra VioletImaging Telescope (UVIT) on-board the Indian space satellite, AstroSat, withthe Hubble Space Telescope UV Globular Cluster Survey (HUGS) data for thecentral region (within $\sim$ $\ang[angle-symbol-over-decimal]{;2.7;} \times\ang[angle-symbol-over-decimal]{;2.7;}$) and Gaia and ground-based opticalphotometry for the outer parts of the cluster. We constructed the UV andUV-optical color-magnitude diagrams, compared the horizontal branch (HB)members with the theoretical zero-age HB and terminal-age HB models andidentified 34 UV-bright stars. The spectral energy distributions of theUV-bright stars were fitted with theoretical models to estimate their effectivetemperatures (12500 K - 100,000 K), radii (0.13 to 2.2 $R_{\odot}$), andluminosities ($\sim 40$ to $3000$ $L_{\odot}$) for the first time. These starswere then placed on the H-R diagram, along with theoretical post-HB (pHB)evolutionary tracks to assess their evolutionary status. The models suggestthat most of these stars are in the AGB-manqu\'e phase and all, except three,have evolutionary masses $<$ 0.53 $M_{\odot}$. We also calculated thetheoretically expected number of hot post-(early)-AGB (p(e)AGB) stars in thiscluster and found the range to match our observations. Seven UV-bright starslocated in the outer region of the cluster, identified from the AstroSat/UVITimages, are ideal candidates for detailed follow-up spectroscopic studies.

The First Extensive Exploration of UV-bright Stars in the Globular Cluster NGC 2808