Hubble Helix Observations ("HELIX")

For the 14 hours of peak Leonid meteoroid flux in November 2002, the Hubble Space Telescope was pointed away from the radiant, and the solar arrays were oriented to minimize their cross-section. By coincidence, one of the nearest and largest planetary nebulae, the Helix Nebula (NGC 7293), was nearly opposite the incoming Leonids and could be observed. A Hubble Helix Team of volunteers, led by Margaret Meixner (STScI), organized a nine-orbit campaign to observe the Helix with the ACS, WFPC2, NICMOS, and STIS. A contiguous 3x3 grid of 4k by 4k-pixel ACS images covering much but not all of the Helix was exposed in two filters, Ha+[N II] (F658N) and [O III] (F502N). The WFPC2 images, obtained in parallel, covered portions of the nebula in [O I] (F631N), He II (F469N), or Ha (F656N). NICMOS/NIC3 observations were obtained at two locations on the nebula and two off NICMOS/NIC3 observations were obtained at five locations on the nebula and four off. A few of the STIS parallel observations in [O II] (F28X50OII) were located on the nebula, but most were located off the nebula.