ESA shares Hubble image of Cat's Eye Nebula ejecting mass equal to our solar system

Celebrating International Cat Day, the European Space Agency (ESA) has shared a ‘purrfect’ picture of a nebula resembling the felines on Earth. Located three thousand light-years away from Earth, the nebula is named the Cat's Eye nebula for the shapes generated by the ejection of glowing gas as the central star approaches the end of its life. According to the agency, the nebula, also called NGC 6543, was discovered by William Herschel in 1786 and remains an interesting target for ground-based astronomers. 

Hubble telescope observes Cat's Eye nebula

The picture was first released back in 2008 and the nebula was photographed using the NASA-ESA Hubble telescope's Advanced Camera for Surveys (ACS). Interestingly, the picture clearly highlights a pattern of multiple concentric rings, or shells, around the Cat's Eye. According to NASA, each of these rings represents the edge of a spherical bubble seen projected onto the sky, a phenomenon that explains the nebula's brightness on the outer edge. 

After years of observations, astronomers concluded that the star at the nebula's center ejected its mass in a series of pulses at 1,500-year intervals. Surprisingly enough, these ejections resulted in dust shells that have a mass equivalent to all the planets in our solar system combined, although just 1% of the mass of the sun. 

"The bull's-eye patterns seen around planetary nebulae come as a surprise to astronomers because they had no expectation that episodes of mass loss at the end of stellar lives would repeat every 1,500 years", NASA explained in one of its descriptions of the nebula. Through multiple theories, astronomers have tried to explain the reason for the loss of mass of the central star. The theories suggest that the reason might be cycles of magnetic activity somewhat similar to our own Sun's sunspot cycle, the action of companion stars orbiting around the dying star, and stellar pulsations.

Another interesting theory suggests that the star first smoothly ejects the materials which are then transformed into rings due to the formation of waves in the outflowing material.