Aditya-L1 catches Sun's early warning signs before Solar flares

Aditya-L1 catches Sun's early warning signs before Solar flares

Chennai, Aug 29 (UNI) India's first sun exploratory mission Aditya-L1 satellite have found Sun's early warning signs before eruption of major solar flares.

PSLV-C57, in its 59th flight of PSLV and 25th mission using PSLV-XL configuration, took off from Second Launch Pad (SLP), SDSC, SHAR on September 2, 2023 and injected the Aditya-L1 spacecraft in a highly eccentric Earth bound orbit

ISRO in an update on Saturday said, scientists using India's first dedicated solar observatory, Aditya-L1, have found small, short-lived brightening in the Sun's atmosphere that appear in the hours before a major solar flare erupts and that cluster around the very spot where the flare later occurs.

The result, published in the Monthly Notices of the Royal Astronomical Society (MNRAS), draws on simultaneous ultraviolet (UV) and X-ray observations from three payloads of the Aditya-L1 mission.

Solar flares are sudden and intense bursts of electromagnetic radiation from the Sun. It is understood to result from the release of magnetic energy. Large flares can disrupt radio communication, interfere with navigation systems, damage satellites, and increase radiation hazards for astronauts and spacecraft.

Understanding how solar flares are triggered is therefore essential for improving space weather forecasting and protecting modern technological infrastructure, the Space Agency said.

It said by observing the Sun continuously from the Sun–Earth Lagrange Point 1 (L1), Aditya-L1 provides an uninterrupted view of solar activity across multiple wavelengths. The Solar Ultraviolet Imaging Telescope (SUIT) observes the Sun in eleven near-ultraviolet (NUV) filters, revealing different layers from the upper photosphere to the chromosphere. NUV wavelengths largely inaccessible from the ground because Earth's atmosphere absorbs most ultraviolet radiation.

Complementing SUIT are two X-ray instruments, the Solar Low Energy X-ray Spectrometer (SoLEXS) and the High Energy L1 Orbiting X-ray Spectrometer (HEL1OS), which measure the X-ray emission produced by energetic processes in the solar corona.

Combining these data scientists study how activity in the lower solar atmosphere is linked to energy release in the corona during the build-up to a flare.

Analysing several solar flare events in the Mg II h filter of SUIT, the team found numerous small, short-lived brightening known as transient events -- occurring in active regions before the onset of major flares. Some of these also showed corresponding X-ray signatures, indicating that they involve the release of magnetic energy. These pre-flare transient events clustered around the location where the major flare later occurred. The results suggest that repeated small-scale energy release may progressively destabilise the magnetic field in an active region, eventually leading to a large solar flare.

This study represents one of the first systematic investigations of pre-flare activity using simultaneous ultraviolet imaging and X-ray observations from a single observatory.

The findings provide valuable insights into the physical processes that trigger solar flares and move scientists a step closer towards reliable flare forecasting -- which will ultimately contribute to better space weather prediction, helping protect satellites, astronauts, communication systems and other critical technologies.

The study, led by researchers from the Manipal Centre for Natural Sciences (MCNS), Manipal Academy of Higher Education (MAHE), along with scientists from ISRO/Department of Space and other academia demonstrates the growing scientific impact of India's flagship solar mission, Aditya-L1.

After taking off from the spaceport of Sriharikota, the spacecraft performed orbital maneuvers by using its LAM reached the Sun-Earth Lagrange point L1 (1.5 million kms from Earth, in a halo orbit) after a four-month long journey.

As the spacecraft travelled towards L1, it exited the Earths’ gravitational Sphere of Influence (SOI). After exit from SOI, the cruise phase started and subsequently the spacecraft was injected into a large halo orbit around L1. The total travel time from launch to L1 took about four months for Aditya-L1.

Upon arrival at the L1 point, another manoeuvre took Aditya-L1 to an orbit around L1, a balanced gravitational location between the Earth and the Sun.

Aditya­L1 is the first Indian space-based observatory to study the sun from a halo orbit around first sun­ earth Lagrangian point (L1), which is located roughly 1.5 million km from earth.

A satellite placed in the halo orbit around the L1 point has the major advantage of continuously viewing the Sun without any occultation/eclipse. This will provide a greater advantage of observing the solar activities continuously.

The strategic placement at the L1 Lagrange point ensures that Aditya-L1 can maintain a constant, uninterrupted view of the Sun. This location also allows the satellite to access solar radiation and magnetic storms before they are influenced by Earth's magnetic field and atmosphere.

Aditya-L1 is a satellite dedicated to the comprehensive study of the Sun. It has 7 distinct payloads developed, all developed indigenously--five by ISRO and two by Indian academic institutes in collaboration with ISRO.

Aditya in Sanskrit means the Sun. L1 here refers to Lagrange Point 1 of the Sun-Earth system. For common understanding, L1 is a location in space where the gravitational forces of two celestial bodies, such as the Sun and Earth, are in equilibrium.

This allows an object placed there to remain relatively stable with respect to both celestial bodies.

The spacecraft has seven payloads to observe the photosphere, chromosphere and the outermost layers of the Sun (the corona) using electromagnetic and particle detectors. Using the special vantage point of L1, four payloads will directly view the Sun and the remaining three payloads will carry out in-situ studies of particles and fields at the Lagrange point L1.

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