The Sun is rather quiet. That’s the premise of my novel “Silent Sun.” But now researchers at the Max Planck Institute for Solar System Research (MPS) in Göttingen, Germany have also proved it with a systematic comparison published in Science. In such analyses, of course, it is important to make sure you are not comparing apples with oranges. Red dwarfs, for example, are considered much more active. But even among the class of yellow dwarfs like the Sun, there can be big differences.
Therefore, the researchers selected candidate stars that were similar to the Sun in terms of important characteristics. In addition to surface temperature, age, and proportion of heavy elements, another characteristic was rotational velocity. “The speed at which a star rotates about its own axis is a crucial variable,” says Sami Solanki, director at MPS and co-author of the study.