Inconstant north star
Posted: Sat Apr 29, 2023 8:11 pm
It is well known that Polaris (the north star) is a Cepheid variable, but its periodic brightness variations have been steadily decreasing in amplitude for the last hundred years. Around the beginning of the 20th Century, Polaris’ brightness fluctuated every four days by 10%. Only ten years ago this variation had dropped to 2%, but recent observations display an increase in variability to 4%. Polaris is an odd star in that it is a Cephid variable with a declining variability, and now astronomers are baffled as to why the brightness fluctuation has been revived…
Oh well, in only 13,000 years Thuban will be the north star, so it's only a temporary thing....
Oh well, in only 13,000 years Thuban will be the north star, so it's only a temporary thing....