240411 - Abell2151 Hercules Galaxy Cluster
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click image to enlarge
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ASTRO:
type=galaxy cluster (starscape) const=Hercules mag=15-13 dist~500 M ly size~6 M ly (image boundary) IMAGE: location=EB Driveway BrtlCls=4 moon=13% WxCr exposure=CMOS OSC: 52x180s (2.6h), G100 EQUIPMENT: camera=ZWO ASI2600MC-Pro optics=ES102 w24mmEP 1.7x prjctn, F=1238mm, f/12.1 (eff) filter=Optolong L-Pro LPS mount=Celestron AVX guiding=Orion 60x240mm, ZWO ASi224MC SOFTWARE: acquisition=Stellarium, APT, PHD2, processing=PixInsight, RCAstro, PhotoshopCC, APF-R, Lumenzia, LrC |
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Taking the term “deep sky” to a whole new level, this cluster of galaxies makes-up what is known as the Hercules Cluster, an archipelago of island universes lying an astounding 500 million light-years away. Also known as Abell 2151, this cluster is rich with gas, dust and star-forming spiral galaxies, some of whom are interacting (merging). It also contains elliptical galaxies, which lack as much gas and dust and associated newborn stars as their spiral cousins, but tend to show more brightly. The image makes visible more than 70 individual galaxies. With larger and more powerful equipment, counts have ranged as high as 500 within the same field of view.
The cluster's official designation of Abell 2151 reflects that it is a member of the catalog of rich northern galaxy clusters originally published by American astronomer George O. Abell. Abell’s research stands as an important cornerstone to today's understanding of the structure of the Universe. Led by this cluster, younger contemporaries have continued to build on Dr. Abell's legacy, by determining the group is part of the larger Hercules Supercluster, which is itself part of the much larger Great Wall super-structure.
By switching our thinking away from the space-continuum and toward the time-domain, the wonder of the image begins to take-on extreme significance. We are looking back through time to a part of the Universe as it existed appx 500 million years ago! …meaning the light we see left there and began its trek toward us at about the time when Fossil evidence here on Earth marks the beginning of the Cambrian explosion of life, which established the main species of modern life as it began to climb out of the aquatic environs of the planet onto dry land.
The colors in this remarkably "deep" image clearly show the star forming galaxies with a blue tint and galaxies with older stellar populations with a redish cast. The image spans about 3/4 of an arc-degree across the cluster center, corresponding to over 6 million light-years across at the cluster's estimated distance. Many galaxies seem to be colliding or merging while others seem distorted - clear evidence that cluster galaxies commonly interact. In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.
For observers who own or have access to a large telescope (recommended 12" and larger) and a dark viewing site, the Hercules Cluster is one of the most impressive sights in our nighttime sky. For imagers, the Cluster is best captured with a larger scope, typically 150mm (appx 6”) or better; however, with longer imaging sessions and good focusing techniques, some of the detail can be captured with more moderately sized equipment.
The cluster's official designation of Abell 2151 reflects that it is a member of the catalog of rich northern galaxy clusters originally published by American astronomer George O. Abell. Abell’s research stands as an important cornerstone to today's understanding of the structure of the Universe. Led by this cluster, younger contemporaries have continued to build on Dr. Abell's legacy, by determining the group is part of the larger Hercules Supercluster, which is itself part of the much larger Great Wall super-structure.
By switching our thinking away from the space-continuum and toward the time-domain, the wonder of the image begins to take-on extreme significance. We are looking back through time to a part of the Universe as it existed appx 500 million years ago! …meaning the light we see left there and began its trek toward us at about the time when Fossil evidence here on Earth marks the beginning of the Cambrian explosion of life, which established the main species of modern life as it began to climb out of the aquatic environs of the planet onto dry land.
The colors in this remarkably "deep" image clearly show the star forming galaxies with a blue tint and galaxies with older stellar populations with a redish cast. The image spans about 3/4 of an arc-degree across the cluster center, corresponding to over 6 million light-years across at the cluster's estimated distance. Many galaxies seem to be colliding or merging while others seem distorted - clear evidence that cluster galaxies commonly interact. In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.
For observers who own or have access to a large telescope (recommended 12" and larger) and a dark viewing site, the Hercules Cluster is one of the most impressive sights in our nighttime sky. For imagers, the Cluster is best captured with a larger scope, typically 150mm (appx 6”) or better; however, with longer imaging sessions and good focusing techniques, some of the detail can be captured with more moderately sized equipment.