| Name: Nishad Prashant Kumar Bunnelal |
| Affiliation: Inter University Centre for Astronomy and Astrophysics |
| Conference ID: ASI2026_490 |
| Title: NIR Census Of RR Lyrae stars & Horizontal Branch Morphology in Globular Clusters |
| Abstract Type: Poster |
| Abstract Category: Stars, Interstellar Medium, and Astrochemistry in Milky Way |
| Author(s) and Co-Author(s) with Affiliation: Prashant Nishad(Inter-University Centre for Astronomy and Astrophysics, Pune - 411007, India), Anupam Bhardwaj(Inter-University Centre for Astronomy and Astrophysics, Pune - 411007, India), Susmita Das(Inter-University Centre for Astronomy and Astrophysics, Pune - 411007, India) |
| Abstract: Probing the morphology of Horizontal Branch stars and RR Lyrae variability is important for understanding the Stellar evolution of low-mass stars. We present a census of Horizontal Branch (HB) and RR Lyrae stars in M2, M3, M5, M14, M15, M53, and NGC 6934 Globular Clusters (GCs) for the first time in NIR (JHKs) wavelengths. Our time-series observations have been collected using the WIRCam instrument on the 4-m Canada--Hawaii--France Telescope. We investigate the effect of metallicity and wavelength on HB morphology and RR Lyrae variability in GCs, and explore globular clusters with similar metallicity showing different HB morphologies. The long-standing "second-parameter problem” will be investigated using our observational data and theoretical models generated from the MESA (Module for Experiments in Stellar Astrophysics) Stellar evolution code, focusing on peculiar clusters like NGC 6441 and NGC 6388. We will also present RR Lyrae Period-luminosity relations for the first time with unprecedentedly small scatters of 0.05 mag in clusters of different mean metallicities, establishing their use as population II distance indicators. |
