NGC 6772 NGC 6778 ety in my second survey with the 3½-inch telescope. It was a full magnitude dimmer than what I had recorded the limiting magnitude of the telescope in my first survey to be. Afterwards, I'd use NGC 6778 and other planetaries of its ilk to verify the limiting magnitude of the 3½-inch, and I still occasionally turn to the nebula as an observing bellwether. If I can hold it steady with the 3½-inch at 130× using the O III filter, then I consider the transparency to be better than average. NGC 6772 TYC 5133-1070-1 115 IRAS 19119-0241 112 TYC 5133-1049-1 117 Barnard 139 NGC 6778 is accompanied by an 8.5-magnitude star (HD 180974) some 4.9′ to the east-northeast. I'd like to think I may have detected Barnard 139, the dark nebula looming north-northwest - but I may need to return for another look. Slew to a spot 6¾° almost due north of Delta Aquilae to arrive at the site of our next target, Vy 2-2. My 7-inch at 160× in a 17′ eyepiece field shows a small, inverted triangle of 10th- to 12th-magnitude stars. NGC 6778 HD 180974 85 BD-30 4527 109 20′ × 20′ 20′ × 20′ CELESTIAL INTERSECTIONS To snag NGC 6772 you can avail yourself of several imaginary lines connecting stars as shown above. Moreover, a line dropped 6.4′ south from the 11.2-magnitude star at the center of the line of three stars intersects the longer imaginary line. These aids should guide you to your target. BUTTERFLY SURPRISE This finder image shows NGC 6778 to be an indistinct ovate shape, but applying multiple filters brings out the planetary nebula's pretty bowtie silhouette, as can be seen at top. sk yand tele scope .o r g * JULY 2023 31 NGC 6772 PHOTO: GARY IMM; NGC 6772 FINDER IMAGE: POSS-II / STSCI / CALTECH / PALOMAR OBSERVATORY; NGC 6778 PHOTO: GARY IMM; NGC 6778 FINDER IMAGE: POSS-II / STSCI / CALTECH / PALOMAR OBSERVATORYhttp://skyandtelescope.org