Indian solves 400-year-old sunspot mystery
A Calcutta physicist and two US scientists have solved a 400-year old mystery on the working of the sun, offering a solution that could help predict space weather and plan space missions and polar flights.
Dibyendu Nandy at the Indian Institute of Science Education and Research (IISER) in Calcutta and American scientists Andres Munoz-Jaramillo and Petrus Martens have explained unusual recent sunspot behaviour in findings published on Wednesday in the journal Nature.
The scientists found that variation in speed of flow of plasma within the sun towards its equator affects the frequency of sunspots. Sunspots are dark spots occasionally seen on the surface on the sun, which are focal points of magnetic energy on the solar surface that affect space weather including on and near the earth. But the work also helped gain insight into the working of sunspots that has eluded scientists since sunspots were first known to have been observed four centuries ago.
“The work has helped us understand why the sun spots disappeared for an inordinately long period of time towards the end of the last solar cycle,” Nandy told Hindustan Times, hours before a global teleconference on the findings that have left the global astrophysics community excited.
The work offers the possibility for short term forecasts of space weather. “We can now take our simulation model forward to predict space weather, which can be used to schedule space missions and air traffic near polar regions (which are most affected by sunspot-caused weather changes),” Nandy added.
The sun’s output energy is the principal natural input that affects space climate, including the climate near the earth. The solar energy output was believed to be a constant till the mid 20th century.
Solar energy output is now understood to be a result of a dynamo mechanism within the sun, converting the energy of plasma flow beneath the surface of the sun to magnetic energy foci on the surface that are observed in the form of sunspots.