The mystery of the 4-century-long solar cycle interruption lasting 70 years is expected to be unraveled through the discovery of HD 166620, a star undergoing a similar phenomenon.
According to Science Alert, the strange phenomenon observed from 1645 to 1715 by many renowned astronomers, including Galileo Galilei, is known as the “Maunder Minimum.”
Solar variation in a typical 11-year cycle – (Photo: NASA).
Typically, the Sun operates on a stable 11-year cycle: it starts off calm, then gradually intensifies with a flurry of solar storms, becoming fierce before tapering off in the remaining part of the cycle. However, during that 70-year “hibernation,” sunspots ceased to appear, meaning the Sun suddenly became eerily calm and gentle.
Of course, scientists cannot turn back time to learn more about the Maunder Minimum. To solve this mystery, physicist Anna Baum from Lehigh University and her colleagues have been monitoring 59 stars with characteristics similar to the Sun for several decades, according to PHYS.
Ultimately, they identified HD 166620 as exhibiting similar behavior. It previously operated on a 17-year cycle but has not shown any sunspots since 2003.
HD 166620 is a star located 36 light-years away, with a size and mass about 80% that of the Sun and is approximately 6 billion years old.
The discovery of a “twin” exhibiting this hibernation behavior suggests that our Sun is not alone. HD 166620 will be studied further to understand what led to this mysterious minimum phase and may provide additional data to help us learn more about our Sun, serving as a mirror.
The study was recently published in the Astronomical Journal.
