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IIA finds a novel way to explore the sun’s secrets by studying solar magnetic fields

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Last Updated24/08/2024

Astronomers have found a new way to probe deeper into the sun’s secrets by studying the magnetic field at different layers of the solar atmosphere.

Astronomers at the Indian Institute of Astrophysics (IIA) have made a significant breakthrough in solar studies by developing a new method to probe the sun’s magnetic field across various layers of its atmosphere.
Using data from the Kodaikanal Tower Tunnel Telescope, these researchers are delving deeper into the enigmatic processes that govern the sun’s behavior, offering fresh insights into the complex magnetic interactions within the solar atmosphere.

The solar atmosphere is composed of multiple layers, each interconnected by magnetic fields that play a crucial role in transferring energy and mass from the sun’s interior to its outermost layers. This process, often referred to as the "coronal heating problem”.
The magnetic field is also the primary driver of the solar wind, which impacts space weather and, consequently, Earth’s own environment.

The IIA astronomers have focused their research on an active region of the sun, specifically a sunspot characterized by complex features such as multiple umbrae and a penumbra.
By utilizing simultaneous observations in the Hydrogen-alpha (6562.8 Å) and Calcium II 8662 Å spectral lines from the Kodaikanal Tower Tunnel Telescope, they have been able to infer the magnetic field’s stratification across various heights in the solar atmosphere.
The Kodaikanal Solar Observatory, operated by the IIA, houses the Tunnel Telescope equipped with a three-mirror setup known as a Coelostat. This configuration allows for precise tracking of the sun as it moves across the sky.
The primary mirror (M1) rotates to follow the sun, while the secondary (M2) and tertiary (M3) mirrors redirect and align the sunlight into a horizontal beam, which is then focused by an achromatic doublet. This system enables the capture of high-resolution images of the sun with an image scale of 5.5 arcseconds per millimeter.

Traditionally, the chromospheric magnetic field has been studied using spectral lines such as Calcium II 8542 Å and Helium I 10830 Å. However, these lines have limitations in their diagnostic capabilities, particularly when applied to diverse solar features.