Polaris is Getting Brighter, and Has Been for a While

For those of you who are currently lost in the woods (but also have access to, take note of the ongoing changes being observed in the famed homing beacon Polaris, or the “North Star.”  Though the star has decreased in brightness over the last few decades, a closer look at historical observations of Polaris has shown that in the long run, the star has actually been brightening for a long time.

Astronomers have known since the early 20th century that The North Star fluctuates in brightness. This puts it in a class of stars called Cepheid variables, which can regularly change in intensity – kind of like that flickering light bulb in the bathroom that nearly gives you a shower seizure every morning. Recently, however, scientists have found that even with the intermittent flickering, Polaris has been getting progressively brighter in the grand scheme of things.

Polaris 6 IN POST

Desperation-prone hikers can rest easy knowing Polaris will be brighter than ever the next time they take a wrong turn. (Greg Bacon, STSc)

Scott Engle of Villanova University set out to get a broader perspective on this star’s brightness record. To do this, he consulted a century’s worth of data that was originally procured with a wide variety of telescopes and imaging instruments. Engle even had to seek out those older instruments and put them to back to work – this being the only way he could compare their findings 50 years ago to what they’d find today. In the end, Engle found that the star has been getting brighter for at least 100 years.

But Engle couldn’t stop there. After examining the Polaris data of the last century, he figured he might as well do the same for all of recorded history. Engle consulted observations made by Tycho Brahe in the 16th Century (who I’m assuming also made remote control cars) and Abd al-Rahaman al-Sufi in the 10th Century, to see how bright Polaris was in their respective eras. Taken at face value, the data recorded by both of these astronomers indicates that the North Star could be as much as 4.6x brighter than it was in ancient times.

al-Sufi IN POST

al-Sufi’s “Book of Fixed Stars.” Engle reached all the way back to the first millennium to gather ancient data on Polaris. (Wikipedia)

How much brighter will Polaris get this millennium? What other astronomical insights can be gained from ancient documentation? Can these transformations in Polaris also be observed in the defunct Minnesota North Stars of the NHL? Speculate on only this last question below.


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