Stephan's Quintet (Galaxy Group in Pegasus)
Stephan's Quintet is a group of five galaxies, set to the right side of this image. Those galaxies that are actually physically related within the cluster (at least three and probably four of the galaxies in the tight grouping) have been "dancing" for several billion years and they show considerable distortion (zoom in or look at the separately processed image). The galaxies will probably merge in the next 5 or so billion years.
Three of the galaxies are part of a true galactic cluster, while at least one of the other two is only coincidentally in the line of sight. In addition to the five galaxies in the group (two are intertwined and essentially look like one), there are several other galaxies in this image.
The largest galaxy, right of center is NGC 7320, located about 50 million light years away. Directly above it is NGC 7219, located about 135 million light years away. The two intertwined galaxies to the upper right of NGC 7230 are designated NGC 7318A and 7318B. NGC 7318A is about 285 million light years away, while the close NGC 7318B is only 245 million light years away. If you zoom in, you can see considerable detail in the distorted spirals, a relict of heavy interaction between the two galaxies when they were closer than they are currently.
The fifth of the Quintet is starlike, and is the lower-left member of the pair of equally bright stars to the lower right of the other four. NGC 7317 is also about 275 million light years distant.
To the upper left of NGC 7320, and further away visually, is the fainter galaxy NGC 7320C, also located about 250 million light years away -- also part of the physical galactic cluster.
Near the bright star near the left border, slightly below center, is the clear spiral LEDA 141041, another member of the physical cluster at about 260 million light years.
Harder to detect, about halway between NGC 7320 and LEDA 141041 (slightly closer to NGC 7320) is PGC 692246, for which I have no estimated distance.
Object: Stephan's Quintet and general region
Venue: Rancho del Rio Observatory
Date: September 27, 2013
Optics: Celestron C9.25 with f/6.3 focal reducer
Guiding: B&L 4" SCT piggybacked with PhD
Camera: Nikon D5100 at prime focus
Exposure: 93 120-sec exposures at ISO 1600 (total exposure, 3hr, 6min)
Stacking: DeepSky Stacker with flats and darks
Processing: PhotoShop CS6
Stephan's Quintet (Galaxy Group in Pegasus)
Stephan's Quintet is a group of five galaxies, set to the right side of this image. Those galaxies that are actually physically related within the cluster (at least three and probably four of the galaxies in the tight grouping) have been "dancing" for several billion years and they show considerable distortion (zoom in or look at the separately processed image). The galaxies will probably merge in the next 5 or so billion years.
Three of the galaxies are part of a true galactic cluster, while at least one of the other two is only coincidentally in the line of sight. In addition to the five galaxies in the group (two are intertwined and essentially look like one), there are several other galaxies in this image.
The largest galaxy, right of center is NGC 7320, located about 50 million light years away. Directly above it is NGC 7219, located about 135 million light years away. The two intertwined galaxies to the upper right of NGC 7230 are designated NGC 7318A and 7318B. NGC 7318A is about 285 million light years away, while the close NGC 7318B is only 245 million light years away. If you zoom in, you can see considerable detail in the distorted spirals, a relict of heavy interaction between the two galaxies when they were closer than they are currently.
The fifth of the Quintet is starlike, and is the lower-left member of the pair of equally bright stars to the lower right of the other four. NGC 7317 is also about 275 million light years distant.
To the upper left of NGC 7320, and further away visually, is the fainter galaxy NGC 7320C, also located about 250 million light years away -- also part of the physical galactic cluster.
Near the bright star near the left border, slightly below center, is the clear spiral LEDA 141041, another member of the physical cluster at about 260 million light years.
Harder to detect, about halway between NGC 7320 and LEDA 141041 (slightly closer to NGC 7320) is PGC 692246, for which I have no estimated distance.
Object: Stephan's Quintet and general region
Venue: Rancho del Rio Observatory
Date: September 27, 2013
Optics: Celestron C9.25 with f/6.3 focal reducer
Guiding: B&L 4" SCT piggybacked with PhD
Camera: Nikon D5100 at prime focus
Exposure: 93 120-sec exposures at ISO 1600 (total exposure, 3hr, 6min)
Stacking: DeepSky Stacker with flats and darks
Processing: PhotoShop CS6