| Name: Hardik Medhi |
| Affiliation: National Centre for Radio Astrophysics |
| Conference ID: ASI2026_159 |
| Title: Reviving Interplanetary Scintillation Studies with the Ooty Radio Telescope |
| Abstract Type: Poster |
| Abstract Category: Sun, Solar System, Exoplanets, and Astrobiology |
| Author(s) and Co-Author(s) with Affiliation: Hardik Medhi(National Centre for Radio Astrophysics, Pune - 411007, India), Divya Oberoi(National Centre for Radio Astrophysics, Pune - 411007, India), M. A. Krishnakumar(National Centre for Radio Astrophysics, Pune - 411007, India) |
| Abstract: The solar wind is a neutral plasma that constantly flows out of the Sun's corona and permeates the interplanetary space. The density irregularities cause the plane wavefronts from a distant compact radio source to develop phase corrugations as the waves travel through the plasma. By the time they reach the Earth, these phase corrugations grow into amplitude fluctuations. The solar wind's relative motion transforms these spatial variations into temporal intensity scintillations, also called Interplanetary Scintillations (IPS). IPS can monitor the solar wind in a vast swathe of interplanetary space revealing large scale structures in the normal solar wind, and characterising any variations in the interplanetary medium due to features and activities on the Sun. Commissioned in 1970, the Ooty Radio Telescope (ORT), designed to work at 326.5 MHz, has been used to pursue cutting-edge IPS studies for multiple decades. Sitting on a natural North-South slope of 11°, its 530m North-South and 30m East-West antenna allows the ORT to track celestial objects for almost ten hours in the East-West direction with high sensitivity. The telescope is currently being revived to reach and surpass legacy-level sensitivity. We have been using the ORT to observe a handful of known IPS sources since June 2025, fortuitously overlapping with the peak of the current solar cycle, to probe the interplanetary medium from ~0.1 AU to ~1 AU. We have computed the basic IPS observables - scintillation index and power spectrum - and obtained the m-p curves for a few strong sources. We have identified a few coronal mass ejections (CMEs) which crossed our IPS lines-of-sight. Here we present the current status of our study. Our work already demonstrates that the ORT is producing data suitable for investigations of the interplanetary medium for space weather applications. |
