Nebulae

The Iris Nebula

(NGC 7023 or Caldwell 4)

photo by Geoffrey Heller

The Iris Nebula

Date TakenAugust 31, 2008
LocationOlympic Peninsula, Washington USA
Exposure60 minutes @ 10 minute subs
ClassificationReflection Nebula
ConstellationCepheus
Distance1,300 Light Years
NotesNote that dark clouds of gas in the four cardinal directions block light from stars. You can see where the clouds are by looking where the starts are not.
Explanation
NGC 7023 is actually the cluster within the nebula, LBN 487, and the nebula is lit by a mag. +7 star, SAO 19158.

The Pelican Nebula Ionization Front

(IC 5070)

photo by Geoffrey Heller

The Pelican Nebula Ionization Front

Date TakenAugust 24, 2008
LocationTable Mountain (near Ellensburg, Washington USA)
Exposure91 minutes @ 7 minute subs
ClassificationEmission Nebula
ConstellationCygnus
Distance1,800 Light Years
NotesThe large football-shaped star halo in the corner of the photo is an imaging artifact and is not real
ExplanationAn HII region in which star formation is taking place.

The light from young energetic stars is slowly transforming the Pelican's cold gas to hot gas, with the advancing boundary between the two known as an ionization front.

The Ring Nebula

(M 57 or NGC 6822)

photo by Geoffrey Heller

Ring Nebula

The Dumbbell Nebula

(M 27 or NGC 6853)

photo by Geoffrey Heller

Dumbell Nebula