• The Multitude of Molecular Hydrogen Knots in the Helix Nebula 

    Meixner, Margaret; McCullough, Peter; Hartman, Joel; Son, Minho; Speck, Angela K. (Institute of Physics, 2005)
    We present Hubble Space Telescope NICMOS imaging of the H2 2.12 μm emission in five fields in the Helix Nebula ranging in radial distance from 250'' to 450'' from the central star. The images reveal arcuate structures with ...