Here lies my latest version of the Iris Nebula (NGC 7023 or Caldwell 4). It is a bright reflection nebula approximately 1300 light-years away in the constellation of Cepheus and is 6 light-years across (bright blue portion). NGC 7023 is actually the cluster within the nebula (a.k.a. LBN 487). The nebula is lit by the young central star named V380 Cep (mag. +7.1), which is believed to have burst into life just 5,500 years ago in a region containing huge amounts of dust. The bright blueish portion is due to the reflected light in the visible portion of the spectrum. Harder to pickup is the faint reddish brown outer colors resulting from dust absorbing ultraviolet light from the star and releasing it as dim reddish light. Also, researchers using infrared light detectors found that this nebula contains complex carbon molecules known as Poly Aromatic Hydrocarbons (PAHs).
Several dark nebula appear in this image among them is LDN 1174 just left of the center, LDN 1172 upper central, LDN 1170 near the top, and LDN 1173 just right of the center. Of course the bright yellow star T-Cep on the lower right corner has the geometric pattern from my camera but the other bright stars seem unaffected. Imaging was tough due to the unstable weather but I managed to get more by holding of an waiting for more clear nights.
Lastly, this was the second image made using the ZWO EAF focuser and the first image made using the ScopeBuggy. I have two locations in my yard to image from, one is the astronomy shed and the second is from my front lawn. The weather can changes here at the blink of an eye I got tired of the back and forth. There was some concern that it would not be stable enough for imaging but I made some modifications to it. YouTube: https://youtu.be/6VsdEA4CL3U.
Date: 6-27-19, 6-28-19, 6-30-19, 7-3-19, 7-4-19
Camera: ZWO ASI1600MM-Pro
Telescope: Astro-Tech AT115EDT 115mm Refractor Telescope
Focal Length: 805mm
Focal Reducer: Astro-Tech 0.8x Focal Reducer/Field Flattener for Refractor Telescopes
Mount: Orion Sirius
Filter Wheel: ZWO EFW 8x 1.25"
Filter: ZWO L, R, G, B
Focuser: ZWO EAF
Autoguiding: QHY-5L-II-M attached to an Agena 50mm Guide Scope with Helical Focuser
Exposure: L 248 x 90s, R 60 x 90s, G 57 x 90s, B 59 x 90s
Temp: 8 C
Post Processing: PixInsight, Photoshop, Lightroom