Space: The sun is less magnetically active than similar stars

Science News said:

The sun might be a magnetic slacker.

A census of stars similar to the sun shows that our own star is less magnetically active than others of its kind, astrophysicists report in the May 1 Science. The result could support the idea that the sun is in a “midlife crisis,” transitioning into a quieter phase of life. Or, alternatively, it could mean that the sun has capacity for much more magnetic oomph than it’s shown in the past.

“Our sun could potentially become [as] active” as those other stars in the future, says astrophysicist Timo Reinhold of the Max Planck Institute for Solar System Research in Göttingen, Germany.

A star’s magnetism can drive dramatic outbursts like flares and coronal mass ejections, which can cause chaos on orbiting planets (SN: 3/5/18). When these large ejections from the sun hit Earth, they can knock out satellites, shut down power grids and trigger beautiful auroras. Understanding the sun’s magnetic field is thought to be the key to predicting such outbursts (SN: 6/30/19).

Magnetic fields also can create dark sunspots and bright spots called faculae on a star’s surface. These features change over time as magnetic activity changes, altering a star’s brightness.

Astronomers have been observing the sun’s magnetism through those surface features since Galileo turned a telescope toward the sun in 1610. While the sun’s magnetic activity waxes and wanes in an 11-year cycle, our star has remained fairly calm while humans have been watching. Inferences from certain radioactive elements found in tree rings and ice cores suggest that same overall cycle of magnetic activity has held steady for the last 9,000 years.

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