North Star Is Rapidly Changing

The North Star (Polaris) has brightened by 150% since Ptolemy observed it 2000 years ago, says the American Astronomical Society (see report on Science Now).  If the differences from those in ancient times are real, “these changes are 100 times larger than predicted by current theories of stellar evolution.”  Polaris is also a pulsating Cepheid variable, but its pulses have been erratic lately.  One astronomer surmises, “Polaris may be experiencing a rare and rapidly changing period in its evolution.”

Finding the North Star is a required skill for any northern-hemisphere camper.  It is also a conversation starter on how much science can know about processes that supposedly take billions of years.