Speaker
Description
First Name: Dibyendu
Last Name: Chakrabarty
Email Address: dipu@prl.res.in
Affiliation: Physical Research Laboratory
All Authors: Dibyendu Chakrabarty
Abstract: Aditya-L1 mission is the first observatory class mission from India to understand the Sun, solar wind, heliosphere and space weather. Launched on 02 September, 2023, the Aditya-L1 satellite was placed at a halo orbit around the first Lagrange point of the Sun-Earth system on 06 January, 2024. After performance verification of the payloads, science phase operation of the payloads was started. Aditya-L1 consists of seven experiments. Four experiments in Aditya-L1 are remote sensing experiments to study photospheric, chromospheric and coronal processes while three experiments are designed for in situ measurements of solar wind, energetic particles and interplanetary magnetic field (IMF). Aditya Solar wind Particle EXperiment (ASPEX) is one of the three in situ experiments to investigate solar wind and energetic particles. ASPEX consists of two spectrometers – Solar Wind Ion Spectrometer (SWIS) for low energy primary ion (protons or H+ and alpha particle or He2+) measurements and SupraThermal and Energetic Particle Spectrometer (STEPS) for measurements of suprathermal and solar energetic particles (SEP). Through these two spectrometers, ASPEX can measure solar wind ions from 100 eV to a few tens of MeVs. One of the novel features of ASPEX is its ability to have direction-resolved measurements from a 3-axis stabilized spacecraft giving rise an unprecedented opportunity to understand new aspects of solar wind properties, origin, acceleration, and anisotropy. In recent times, a number of insightful science results have been published based on the ASPEX measurements. Some of these results include the evidence of directional isotropy of quiet time suprathermal ions for short intervals, identification long duration energization of solar wind ions during the interacting interplanetary coronal mass ejection event (ICME) in May-2024 and connection of fluctuations in the direction anisotropy of energetic particle fluxes to the fluctuations in IMF. In this talk, some of these insightful results will be presented.