Structure of NGC 7293

This nebula has an inner disk with a diameter of 8' 19 "(0.52 parsec), a convex disk with a diameter of 12' 22" (0.77 parsec) and an outermost ring with a diameter of 25'( 1.76 parsec). One side of the outermost circle is due to collision with interstellar matter. It is estimated that the inner ring of this planetary nebula has expanded for 6500 years, and the outer ring has expanded for 12 and 100 years, with the expansion rates of 40 km/s and 32 km/s respectively. The main ring contains many hazy nodes, which have been observed in many close-range planetary nebulae.