Open Cluster NGC457 & Sharpless 2-188 (Owl & Dolphin)
Cluster and Planetary nebula in Cassiopiea
Uploaded 11/21/25

This beautiful pairing of dissimilar objects in Cassiopiea is seldom framed with both in one shot, and reveals that the pair is immersed in plenty of red hydrogen in the background. The incredible richness of the MilkyWay in this part of the sky is evident!

The second wider field image is a "Context" shot, taken simultaneously with a field precisely 5x wider to put our two primary targets into context in the surrounding star field. Note to the upper left we have the Gamma Cassiopiea nebulas and below NGC281 shines brightly. The Owl cluster and Dolphin Nebula are surrounded by a wreath of red nebulosity.

Technical Data: 11" f/2.2 RASA astrograph, ASI6200mm + Baader LRGB filters, Integration time = 90m total, Samyang 135mm f/2 - Simultaneous exposure, Happy Jack, Az.

RASA 11
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Samyang 135mm Context Image
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Instrument: RASA 11" f/2.2 Mount: Home Made GEM Camera: ASI6200 MM + LRGB filters Guider: ASI mini w/80mm piggyback refractor Exposure: 90m ( 5 min subs) Location: Happy Jack, Arizona, Elevation: 7000 ft. Sky: Seeing FWHM = 2 arcsec , Transparency 9/10 Outside Temperature: 45 F Image Processing Tools: Maxim DL6: Calibration PixInsight: Alignment, Stacking, Star Removal Photoshop CS2: Curves, Color Correction, Cleanup HOME GALAXIES EMISSION NEBS REFLECTION NEBS COMETS GLOBULARS OPEN CLUST PLANETARIES LINKS