Harding’s Helix Nebula
In 1823 Karl Ludwig Harding (1765-1834) used an 8.5” reflector at Göttingen Observatory (290 km SW of Berlin, Germany) to find the planetary nebula NGC 7293 in Aquarius. It was the only new object that he found. The two Herschel’s missed this PN with their 18.5” reflector, probably because its 15’ field of view was too small.
Harding’s Helix Nebula is the one of the brightest (magnitude 7.3) and one of the largest (18’) PN in the sky. Its age is about 10,600 years, its distance is 655 light years and it is nearly 3 light years across. The mag 13.5 central star is dying and will become a white dwarf.
This image was taken by the HST.
