Abstract Details

Name: Narsireddy Anugu
Affiliation: University of Arizona, USA, Tucson, 85719
Conference ID: ASI2021_196
Title : A study of astronomical long-baseline optical interferometry in India
Authors and Co-Authors : Narsireddy Anugu, University of Arizona
Abstract Type :
Abstract Category : Instrumentation and Techniques
Abstract : The next major milestone in extrasolar planet studies is the characterization of Earth analogs, hoping to detect life through atmospheric biomarkers. Although transit spectroscopy has made a lot of progress in this direction, direct imaging enables efficient characterization by resolving the planet and suppressing the host starlight. Current coronagraphic instruments SPHERE, GPI, and SCExAO deliver landmark results. Still, they are fundamentally limited by the inner working angle of a few λ/D and the sensitivity required for the Earth analog detection and characterization. Near-infrared interferometry leveraging on the long baselines up to hundreds of meters offers some advantages by providing: (i) inner-working angle at the orders of a few milliarcseconds, (ii) speckle suppression through spatial coherence allowing isolating the light of a planet from the host star, and (iii) high astrometric precision at the orders of tens of microarcseconds for determining exoplanet mass and its orbit. For instance, VLTI/GRAVITY interferometer has demonstrated breakthrough results with a record-breaking spectrum and astrometric precision of any directly imaged planet to date. GRAVITY also contributed to the 2020 physics Nobel Prize studying our Galactic Center black hole. This presentation studies the advantages of an optical interferometry facility in India. Leveraging India's leadership and experience in building large interferometry observatories, GMRT and IndIGO, perhaps, the time has come to invest in optical interferometry. Space-based optical interferometry is inevitable for future space exploration -- a preparation in this direction is vital by exploiting the advances in the field triggered by the LISA and Starlink satellites. I will outline a couple of interferometric projects, VLTI/GRAVITY and CHARA/MIRC-X, and their breakthrough scientific results.