BENGALURU: Scientists at the Indian Institute of Astrophysics (IIA) Bengaluru have reported the “first significant” results from the Visible Emission Line Coronagraph (VELC) payload onboard the ADITYA-L1 — India’s maiden solar mission launched on September 2, 2023 by the Indian Space Research Organisation (ISRO) to observe the Sun at Lagrangian point L1.
“Using the unique data obtained with the VELC onboard ADITYA-L1 we were able to precisely estimate the onset time of a coronal mass ejection (CME) that erupted from the Sun on July 16. This is the very first science result from the maiden solar mission of ISRO,” said Senior Professor, IIA and Principal Investigator for the VELC payload, R Ramesh.
Observation of the CMEs as they originate on the Sun and understanding its plasma characteristics is one of the major science goals for the VELC.
The coronagraph was designed and built by the IIA in collaboration with the ISRO to help researchers understand the solar corona and provide data for space weather studies. ADITYA L1 was inserted in its targeted halo orbit on January 6 this year.
“Presently, there are no coronagraphs in operation other than VELC to routinely observe the near-Sun corona and the eruptions there. We were trying to observe a CME during its onset phase and could successfully do it for the event on July 16. This is a study since these types of observations will allow scientists to study the coronal conditions during the onset of a CME, and hence help to model them,” he added.
“With the Sun approaching the maximum phase of the current solar cycle 25, the CMEs are expected to occur frequently everyday. Hence, continuous monitoring of the Sun with VELC is expected to provide valuable scientific data,” said the principal investigator.
The solar cycle is a natural cycle the Sun goes through approximately every 11 years as it transitions between low and high magnetic activity. The number of sunspots and solar activity increase during the solar maximum.
“The CMEs are observed in visible continuum light only when they have propagated well away from the Sun’s surface. However, unique spectroscopic observations with the VELC like in our study, let us study CMEs very close to the solar surface itself for the first time”, said Dr V Muthupriyal of IIA.