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A solar flare erupting on the Sun, seen by NASA’s Solar Dynamics Observatory on 2 October 2014. Credit: NASA/Goddard/SDO.
Four detectors that always face the Sun
Four detectors that always face the Sun
Solar flares are sudden explosions on the Sun that can disrupt satellites and communications on Earth. Each Daksha satellite has four medium-energy detector packages that always face the Sun, giving a sensitive view of the high-energy X-rays from flares, orbit after orbit.
For astronomers: technical details
For astronomers: technical details
The four sunward MEPs cover 20–200 keV with about an order of magnitude more effective area than RHESSI in this band, plus simultaneous background measurement from the anti-sun faces. This enables hard X-ray spectroscopy of the non-thermal electron population in flares, including flares fainter than RHESSI could study, and joint directivity studies with STIX (Solar Orbiter) and Aditya-L1. See Bhalerao et al. 2024, Science with the Daksha High Energy Transients Mission (Experimental Astronomy 57, 23), section “Solar Flares”. All Daksha papers are listed on our Publications page.
What is a solar flare?
What is a solar flare?
The Sun’s surface is threaded with magnetic fields. When these fields become twisted and suddenly snap into a new arrangement, they release a huge amount of energy within minutes: a solar flare. Flares heat gas to more than ten million degrees and accelerate electrons to nearly the speed of light, producing light of every kind, from radio waves to gamma rays. Large flares can disrupt radio communications and GPS, and endanger satellites and astronauts.
Why high-energy X-rays?
Why high-energy X-rays?
When the fast electrons in a flare crash into denser gas, they give off “hard” (high-energy) X-rays. These X-rays are the most direct way to measure how many electrons were accelerated and how much energy they carry — key to understanding how flares work. The last dedicated mission of this kind, NASA’s RHESSI, stopped observing in 2018.
What Daksha adds
What Daksha adds
Daksha’s four Sun-facing packages will have roughly ten times RHESSI’s collecting area in this energy range, and will observe the Sun whenever it is in view. Because the other faces of the satellite point away from the Sun, they measure the background at the same time, improving sensitivity further. Combined with observations from other spacecraft, such as ESA’s Solar Orbiter and India’s Aditya-L1, Daksha data will also show whether flares shine differently in different directions.
Support Daksha
Support Daksha
If you would like to see Daksha fly, please take a minute to fill in our short support form. Every response helps show the scientific community’s interest in the mission.
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