Polaris is the Closest, Brightest Cepheid Variable. Very Recently, Something Changed.

The North Star is one of the most important stars in the Northern Hemisphere, guiding travelers for millennia. But it's also one of the most important stars to astronomers since it's the closest example of a classical Cepheid variable. Hubble used these stars to discover that galaxies are moving away from us in all directions. Astronomers have been measuring the brightness of Polaris for over a century, and its pulsation period was slowly increasing, but a few decades ago, the pulsation rate reversed. Polaris has a companion star that orbits every 29 years. Is that the cause?

#astronomy #polaris

http://arxiv.org/abs/2309.03257