For the first time, scientists have obtained high-resolution images of the North Star’s surface using the CHARA Array on Mount Wilson in California. The images revealed previously unknown features on Polaris’ surface, including large bright and dark spots that change over time.
Polaris is a Cepheid variable star, which means it brightens and dims periodically. This predictable behavior makes it an ideal star for measuring cosmic distances. However, the new images show that Polaris may be heavier than expected, with a mass about five times greater than the sun’s.
The spots on Polaris’ surface suggest a 120-day radial velocity variation, which poses a puzzle to scientists. Further observations are needed to understand the mechanism that generates these spots. The study also confirmed the size of Polaris and its distance from Earth, which is about 400 light-years away.
This finding comes as a surprise because Polaris is not just any old star. It’s part of a triple-star system, with one companion orbiting it every 30 years. The team used a speckle interferometer at the Apache Point Observatory in New Mexico to confirm the existence of this companion.
The study was published in The Astrophysical Journal on August 20 and provides new insights into the nature of Polaris and its surface features.
Source: https://www.space.com/north-star-polaris-surface-images