The "Southern Ring Nebula NGC 3132"
Words from Adam Block: "At -40 degrees in declination this object does not climb much higher than 15 degrees above the horizon from the Mount Lemmon SkyCenter. Thus without moving considerably farther south (Chile or Australia!) it is truly rewarding to be able to capture it at all.
A good fraction of the images were taken with only a portion of the telescope mirror seeing the sky while the other fraction stared at the wall inside the observatory. In brightness and form it is second perhaps only to the more famous Ring Nebula. Deeper exposures show an extended, rippled halo of gas."