May 14, 2025
Description: SUIT ADITYA L1 OBSERVATION VIDEO Format : mp4 File Size : 1.5 MB Duration : 00:00:20 Plugin : NA
Observations of a power solar flare and a plasma ejection in UV light by Solar Ultraviolet Imaging Telescope (SUIT) onboard Aditya-L1 Mission: In the movie we see the December 31st, 2023 flare in the SUIT Mg II h channel (280.3 nanometer wavelength). We see the initial eruption and a plasma blob getting ejected from the flaring region and accelerated across the field of view of SUIT. We also see the accelerated part of the ejected loops in the subsequent frames. In this video, the solar disk intensity is suppressed by about a factor of 10 to make it the same intensity as the off-limb structures. The time shown in the movie is given in Universal Time (UT).
On 31 Dec 2023, the Aditya-L1 mission witnessed the Sun unleashing an enormous solar flare (an X-class solar flare) that hurled a glowing plasma 'blob' off the sun. Cameras aboard the SUIT payload of Aditya-L1 watched the rare ejection of plasma blob move from a leisurely 300 kilometer per second speed to a blistering speed of 1500 kilometer per second- with this speed one can circle the entire earth in half a minute. This is first time; such an eruption is caught in near-ultraviolet light which offers scientist a new class of data sets to understand solar phenomena more deeply.
Solar Flares are highly energetic explosions in the solar atmosphere. These are characterized as sudden, intense bursts of energy caused by the release of magnetic energy. During solar flares, a huge amount of radiation is emitted and energetic particles are ejected. These both impact the space weather and geo-space environment, including effects such as disruption in radio communication, power grid disturbances, satellite damage, risk to astronauts and flights etc. Considering the importance of solar flares for technology that is of day to day use, it is of paramount importance to develop a comprehensive understanding of their origin, evolution and properties, with the final aim of being able to predict them substantially in advance so that provisions may be made to shield communication satellites, power grids etc.
Solar flares radiate across the complete electromagnetic spectrum. However, due to sparsity of observations in other wavelengths, they are primarily studied in the X-rays and extreme-ultraviolet, which are towards the higher energy of the electromagnetic spectrum, and to some extent in radio. However, very little is known about their properties in the Near Ultra-violet (NUV) and visible. To develop a comprehensive understanding of flares, it is necessary to, as a first step, develop the complete spectral energy distribution in flares, which can then be complemented with theoretical models, thereby helping us to derive mechanisms of flare and associated radiation.
One of the science goals of the Solar Ultraviolet Imaging Telescope (SUIT) on board Aditya-L1 is to study solar flares in NUV wavelength range of 200-400 nanometers, using 11 different filters. The filters are carefully chosen in such a way that it covers the lower (photosphere) and middle (chromosphere) atmosphere of the Sun. Such observations have never been made before. Therefore, these observations, for the first time, provide the inputs regarding flare radiation which has been missing to date. The Aditya-L1 spacecraft was precisely launched into its intended orbit by PSLV C 57 launch vehicle of ISRO on September 2, 2023. After a series of complex Earth-bound maneuvers, the spacecraft was successfully placed in a large halo orbit around first Sun-Earth Lagrange Point (L1) on January 6, 2024. The first images from SUIT instrument were taken on December 6, 2023. Since then SUIT has gone through and successfully completed the verification and calibration process. From October 2024, SUIT is making regular science observations.
The observation presented here from 31st December, 2023 is from the initial cruise phase before L1 insertion of Aditya-L1 spacecraft. On the eve of the new year 2024 an X-class flare erupted at the east limb of the sun from the active region NOAA 13536 and peaked at ~ 21:55 UT. The flare was also associated with a Coronal Mass Ejection (CME) which exhibited a very high velocity ~ 2852 km/s. The flare consisted of two eruptions. During the cruise phase, the onboard flare detection module was not turned on, and the flare was observed only in the Mg II h (280.3 nm, NB04) channel. SUIT observed a plasma blob getting ejected from the flaring region, which subsequently gets accelerated across the SUIT field of view.
Figure 1. (a) Full disk binned image recorded by SUIT in the Mg II h filter. The over-plotted white dashed box locates the flaring region. (b) GOES SXR 1–8 angstrom observation of the flare. The flare consists of two soft X-ray peaks, which are marked by two black arrows and their corresponding timing. (c) – (h) Time evolution of flare in Mg II h and associated ejected plasma blob located with white arrows. The field of view corresponds to the boxed region shown in panel a.
The velocity of the plasma blob matches closely with the measurements from Atmospheric Imaging Assembly (AIA) onboard Solar Dynamic Observatory (SDO), a NASA mission which has been observing the Sun since 2010. With the larger field of view of SUIT, the plasma blob could be tracked further out into the Solar Atmosphere. The hard X-ray observations from the Spectrometer Telescope for Imaging X-rays (STIX) payload onboard ESA Solar Orbiter (Solo) mission, showed dynamically varying signal during the acceleration phase of the plasma blob. It was also found with the radio observations from Radio Solar Telescope Network (RSTN) and Stereo-A waves, there were multiple type III bursts during the acceleration of the plasma blob. The type III bursts are indicative of acceleration of electrons along the open free magnetic field line. The simultaneous observation of acceleration of the plasma blob, the dynamically varying hard X-ray and the type III bursts signify magnetic reconnection. The SUIT observed blob is cold prominence material suspended in the erupting loop structure, which gets accelerated during the ejection. This observation demonstrates the capability of SUIT in connecting eruptive events like prominences and CMEs back to the solar surface.
Figure 2. STIX hard X-ray 25–50 keV(blue dot-dashed line), and time derivative of GOES 1–8 angstrom (transparent red solid line) over-plotted on RSTN radio spectrogram (panel a) and STEREO-A/WAVES radio spectrogram (panel b). The inset panels A, B, C and D show combined AIA 171 and 1600 A observations during this time. The brown solid vertical lines are the times of inset panels A, B, C, and D. The magenta dashed vertical line marks the start of the acceleration of the plasma blob, as observed from SUIT.
In this research, SUIT observations are used in tandem with data from other observatories like SDO, SolO, RSTN, Stereo-A and GONG (Global Oscillation Network Group). This marks the significance of simultaneous solar observations with multiple instruments, enhancing the observatory-class spirit of Aditya-L1 and highlighting the importance of collaborative observations with ground and space telescopes from across the world.
The above findings are published in The Astrophysical Journal Letters, one of the world’s leading astrophysics journals (DOI 10.3847/2041-8213/adc387).