Why in news
Astronomers at the Indian Institute of Astrophysics (IIA) have found a new way to probe deeper into the sun’s secrets by studying the magnetic fields at different layers of the solar atmosphere.
The astronomers have done this using data from IIA’s Kodaikanal Tower Tunnel Telescope
IIA astronomers have examined an active region (sunspot) with complex features, including multiple umbrae and a penumbra, through simultaneous observations in the Hydrogen-alpha and Calcium II 8662 Å lines from the Kodaikanal Tower Tunnel telescope.
Sunspot
Sunspots (some as large as 50,000 km in diameter) are areas that appear dark on the surface of the Sun (photosphere).
Photosphere is a visible surface of the Sun, from which is emitted most of the Sun’s light that reaches Earth directly.
They appear dark because they are cooler than other parts of the Sun’s surface.
However, the temperature of a sunspot is still very hot —around 6,500 degrees Fahrenheit
They are relatively cool because they form at areas where magnetic fields are particularly strong.
These magnetic fields are so strong that they keep some of the heat within the Sun from reaching the surface.
Magnetic field in such areas is about 2,500 times stronger than Earth’s.
They typically consist of a dark region called the ‘umbra’, which is surrounded by a lighter region called the ‘penumbra’.
In every solar cycle, the number of Sunspots increases and decreases.
The current solar cycle, which began in 2008, is in its ‘solar minimum’ phase, when the number of Sunspots and solar flares is at a routine low.
COMMENTS