NASA | A Flickering X-ray Candle

The Crab Nebula, once considered a steady beacon for X-ray astronomers, has shown unexpected variations in brightness. Observations from 1999 to 2008 revealed fluctuations, and since 2008, a decline in brightness was detected by NASA's Fermi satellite, which also observed gamma ray flares. Scientists believe these changes are due to processes within the nebula's core, powered by a rapidly spinning neutron star. Future research with advanced X-ray telescopes is needed to understand these long-term changes.

What significant changes in brightness have been observed in the Crab Nebula from 1999 to 2008?

What do scientists believe the X rays from the Crab Nebula reveal?

What role does the rapidly spinning neutron star play in the Crab Nebula?

What advancements are needed to better understand the long-term X-ray changes in the Crab Nebula?

How has the perception of the Crab Nebula changed over time according to the text?