Researchers at Nagoya University in Japan have conducted the most detailed simulation of the interior of stars and disproved a theory scientists have believed for 45 years: that stars switch their rotation patterns as they age, with poles rotating faster than the equator in older stars. Scientists have now found that this switch may not occur. Stars maintain solar-type rotation, spinning fast at the equator and slow at the poles throughout their lifetime. The findings are published in Nature Astronomy.
Stars come in many different sizes, temperatures, and colors, ranging from red dwarfs to massive blue giants. Solar-type stars, the focus of this study, are those similar to our sun in mass and temperature. They are medium-sized, yellow stars that provide stable conditions for billions of years, long enough for planets orbiting them to potentially develop life.
Earth rotates as one solid piece, but because the sun is made of hot gas, it rotates differentially —different parts rotate at different speeds. The equator takes about 25 days to complete one rotation while the poles take about 35 days. This is known as solar-type differential rotation.







