Home Galaxy Gallery Nebula Gallery Globular Clusters Open Clusters My Equipment Misc Astro Gallery


NGC 457 - Owl Cluster in Cassiopeia



Scope: Explore Scientific MN152 Maksutov Newtonian at f/4.8, Location:  Pine Creek, Laguna Mountains, CA,   5 August 2016  Camera: ST8300M (Baader Ha LRGB filters)

Exposure: Exposure: 9 x 5 min, (1x1 bin) exposure with UV/IR block,  8 x 2.5 min (2x2 bin) RGB exposures.

Processing: Data Collection -  Sequence Generator Pro (as FITs).  Calibrated, stacked (Kappa Sigma Combine) Deep Sky Stacker, LRGB channel registration and equalization, rough color calibration - Astroart.  Curves, Levels, RGB combine Images Plus. Luminance layering and finishing  - Photoshop. This image is an LRGB combine with Luminance layering. Final color calibration - eXcalibrator. The Luminance construction was the Luminance exposures. Color saturation in LAB color.    Native image size - 3354x2529.  Final Image size is approximately 2600x1950.

North is up in this image. This field lies within the constellation of Cassiopeia. The cluster toward the lower left in NGC 457. It is popularly known as the Owl Cluster and sometimes as the ET Cluster.  The cluster is at a distance of about 7,920 light years from Earth and about 21 million years old.  The other star cluster in the upper right is NGC 436. This cluster is a distance of about light years 9,830 light years and about 84 million years old. The bright yellow star that is one of the Owl's eyes is Phi Cas and is classed a yellow super giant. There are a few small background galaxies just above NGC 475. These objects , selected background galaxies, and some of the bright stars are identified in the annotated image.  This image replaces an earlier image that can be seen in the Archives here. Horizontal FOV is 88'

Image center is approximately - Equatorial 2000: RA: 01h 17m 43s Dec: +5833'51"


All images and content remain the property of Jim Thommes - copyright 2003 - 2016 copyright 2003 - 2012

Current Web Total Hits -

- Unique Visitors