![]() The team discovered and characterised around 100 sub-A class microflares in the quiet corona providing new insight into coronal heating puzzle”, it said. “For the first time, absolute abundances of elemental Mg, Al, Si in the quiet solar corona are derived. A team of scientists from Ahmedabad-based Physical Research Laboratory (PRL), a unit of Department of Space, used observations of the Sun in soft X-rays with Solar X-ray Monitor (XSM) on board ISRO’s Chandrayaan-2 mission during the deepest solar minimum of the past hundred years to learn exciting details about the solar corona, an update on the ISRO website said. The exact reason behind the FIP bias and its origin remains an open question. Global magnetic field of Sun’s atmosphere measured for the first time In more technical terms, these elements have their First Ionisation Potential (FIP) lower than 10 eV, and hence this phenomenon is generally termed as FIP bias. This happens for elements which are easier to ionise, or require lesser energy to ionise. While there are different theories regarding the actual mechanism, one of these relies on the occurrence of a large number of small solar flares called nanoflares.Īnother puzzling observation about the corona is that certain elements are found to have abundances three to four times higher in active regions than in the photosphere. However, this observation is against the natural expectation that the temperatures should reduce as we go away from the source of energy, and this is known as the ‘coronal heating problem.’ From observations, such as the presence of even hotter corona, called active regions above the Sunspots (dark patches seen in visible images of the Sun) where the magnetic fields are known to be stronger, it is suggested that the magnetic fields have an important role in the coronal heating, according to the ISRO. Sunspots help understand life around other stars
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