Science & Instruments

Aditya-L1 carries seven instruments. Four remotely image and analyse the Sun across visible, ultraviolet and X-ray light; three sample the particles and magnetic field streaming past L1 in situ.

Remote-sensing payloads

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VELC — Visible Emission Line Coronagraph

The primary payload, from the Indian Institute of Astrophysics. It images and takes spectra of the Sun's corona very close to the disk, hunting coronal mass ejections and measuring coronal magnetic fields.

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SUIT — Solar Ultraviolet Imaging Telescope

From IUCAA, Pune. It images the photosphere and chromosphere in near-ultraviolet light (200–400 nm) through 11 filters, tracking how energy flows through the lower atmosphere.

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SoLEXS — Solar Low-Energy X-ray Spectrometer

From the U R Rao Satellite Centre. It monitors soft X-rays from the Sun as a star, measuring the flares and temperatures that reveal how the corona is heated.

HEL1OS — High-Energy L1 Orbiting X-ray Spectrometer

Also from the U R Rao Satellite Centre. It captures hard X-rays (10–150 keV) to study the explosive energy release and particle acceleration in solar flares.

In-situ payloads

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ASPEX — Aditya Solar Wind Particle Experiment

From the Physical Research Laboratory. It measures solar-wind protons and heavier ions across a wide energy range, with directional information about the flow.

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PAPA — Plasma Analyser Package for Aditya

From the Space Physics Laboratory, VSSC. It analyses the composition and energy of solar-wind electrons and ions to characterise the plasma around L1.

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Magnetometer — Tri-axial High-Resolution Digital Magnetometers

From the Laboratory for Electro-Optics Systems. Twin sensors on a deployable 6-metre boom measure the interplanetary magnetic field in all three axes, kept far from the spacecraft to avoid interference.

Seven payloads, one star

Between them, these instruments watch the Sun from its visible surface out to the corona, and feel its wind and magnetic field directly — a complete picture from one vantage point.

Key science themes

Coronal heating Coronal mass ejections Solar flares Solar wind & plasma Interplanetary magnetic field Space weather

One of the deepest puzzles Aditya-L1 tackles is coronal heating: the Sun's surface is about 6,000 K, yet its outer corona blazes at over 2,000,000 K. Understanding how energy reaches and heats the corona is central to modern solar physics — and to forecasting the space weather that affects life on Earth.

Recent results

Data from the seven payloads keeps feeding new, peer-reviewed findings about the Sun.

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VELC — watching a CME being born

VELC has captured spectroscopic signatures of a coronal mass ejection's onset, including one tied to a 16 July 2024 flare, an early step toward gauging how fast and how energetic an eruption will be before it fully leaves the Sun.

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SoLEXS — iron's X-ray glow

Across 47 X-class flares in 2024, SoLEXS detected “iron fluorescence” — photospheric iron atoms re-emitting X-rays at 6.40 keV after being struck by a flare's own X-rays. The signal's strength depends on how close to the Sun's centre the flare occurred, giving scientists a new way to judge how high above the surface a flare's energy was released.

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Magnetometer & PAPA — a storm's dawn-side surprise

Combining Aditya-L1's in-situ measurements with a worldwide network of ground magnetometers, scientists led by the Indian Institute of Geomagnetism explained why the two most intense storms of Solar Cycle 25 — on 10 May and 10 October 2024 — produced unusual magnetic disturbances on the dawn side of Earth.

Instrument details from ISRO, eoPortal and Wikipedia. See References & Credits for full attribution.
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