MSV-2035 Astronomy Document - Inside Design - FINAL - FINAL

Astronomy & Astrophysics 51 lensing studies require high quality deep and sharp images. Indian astronomers are involved in such studies using various deep surveys carried out by international teams. Methods based on catastrophe theory have been deployed to predict the number of exotic image formations that can be expected in upcoming surveys, and it has been demonstrated that the expected number is much larger than earlier estimates if one uses realistic lens mapmodels instead of idealized models. 4.1.13 Time DomainAstronomy While time domain astronomy encompasses the study of variability in a variety of astronomical sources, the past few decades has seen an increasing dominance of the studies of transients. The availability of multi-wavelength observational facilities, combined with the longitudinal advantage of the India-based facilities has enabled notable contributions towards studies of transients such as novae, supernovae, gamma-ray burst sources and many other new classes of transients. The AstroSat, the upgraded GMRT and the 3.6-m DOT have added new dimensions towards studying various transients, adding value to expostulate the underlying physics. The combined set of observing facilities in the country have strengthened the international collaborative efforts in the field of time domain astronomy, paving path for the future. The studies of nova systems, both during outburst and at quiescence is one area with significant contribution from India. Optical and infrared spectroscopic studies of the temporal evolution of nova outbursts have revealed Figure 7: Soft-Xray spectra of recurrent nova V3890 Sgr during the supersoft X-ray phase of the 2019 outburst. Based onAstroSat-SXTobservations. Figure credit: Singh et al. 2021, MNRAS, 501, 36. MEGA SCIENCE VISION-2035