NGC 6720 (PK63+13.1)
PN (Planetary Nebulae)
18h 53m 35s
+33Â° 01â€²Â 47â€³
3.0â€œ x 2.4â€œ
Notes – Messier 57
-Â M57, NGC 6720, PK63+13.1, also the Ring, Smoke or Donut Nebula
-Â Bright, pretty large
-Â irregular ring structure
-Â a very impressive and stunning object
-Â small telescope usually show it as a featureless patch or disk, but 4 inch brings out the annular shape
-Â the very blue central star (mag: +15.2) is difficult to see visually
-Â even been suspected of being variable; very good seeing and high power are essential.
-Â much easier to notice is the mag +13.2 star very close outside the ring’s edge.
-Â the nebula’s expansion velocity is 18 miles per seconds!