Object: The Iris Nebula, also known as NGC 7023 and Caldwell 4, is a bright reflection nebula and Caldwell object in the constellation Cepheus. NGC 7023 is the cluster within the nebula, LBN 487, and the nebula is lit by a magnitude +7 star, SAO 19158. It shines at magnitude +6.8. It is located near the Mira-type variable star T Cephei, and near the bright magnitude +3.23 variable star Beta Cephei (Alphirk). It lies 1,300 light-years away and is six light-years across.
Taken: July 26, 2019
Telescope: Astro-Tech 14” RC with 0.65x focal reducer
Mount: Paramount ME II unguided
Camera: ZWO ASI1600MM-Pro (cooled to -15C; unity gain) Bin 2×2.
Focuser: Moonlite Nitecrawler
Filters used: Luminance, Red, Green, Blue on a ZWO 8 position filter wheel
Exposures: Each filter: 25×60 sec. for a total exposure time of 1.67 hours; calibrated with 100 bias frames, 25 dark frames, 32 flat frames with 32 dark-flats
Seeing Conditions:
Processed with PixInsight and Photoshop CC 2019