Stephan's Quintet
Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered.
The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory.
The group is the most studied of all the compact galaxy groups. The brightest member of the visual grouping (and the only non-member of the true compact group) is NGC 7320, where active star formation is occurring.
From the bluish galaxy at the bottom center, NGC 7320, moving clockwise we have NGC 7319, NGC 7318 A and B and NGC 7317. So, 7318 counts as 2 galaxies in the Quintet and note that NGC 7320 is not associated with the other 4 physically linked galaxies but is part of the visual 5 galaxy grouping. It is actually seven times closer to Earth than the other 4 galaxies in the Hickson group (20-30 million light years vs up to 300 million light years for the compact group)). The smaller appearing spiral at left below center is seen referenced in some sources as NGC 7320C.
Four of the five galaxies in Stephan's Quintet form a physical association, a true galaxy group, Hickson Compact Group 92, and will likely merge with each other. Radio observations in the early 1970s revealed a filament of emission between the galaxies in the group. This same region is also detected in the faint glow of ionized atoms seen in the visible part of the spectrum as a green arc. (Wikipedia)
The filament of gas and stellar material can be seen in this image surrounding NGC 7318 A/B at the center.
Capture info:
Location: SkyPi Remote Observatory, Pie Town NM US
Telescope: Officina Stellare RiDK 400mm
Camera: QHY 600M
Mount: Paramount MEII
Data: RGB 30 hours approximately.
Processing: Pixinsight
Stephan's Quintet
Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered.
The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory.
The group is the most studied of all the compact galaxy groups. The brightest member of the visual grouping (and the only non-member of the true compact group) is NGC 7320, where active star formation is occurring.
From the bluish galaxy at the bottom center, NGC 7320, moving clockwise we have NGC 7319, NGC 7318 A and B and NGC 7317. So, 7318 counts as 2 galaxies in the Quintet and note that NGC 7320 is not associated with the other 4 physically linked galaxies but is part of the visual 5 galaxy grouping. It is actually seven times closer to Earth than the other 4 galaxies in the Hickson group (20-30 million light years vs up to 300 million light years for the compact group)). The smaller appearing spiral at left below center is seen referenced in some sources as NGC 7320C.
Four of the five galaxies in Stephan's Quintet form a physical association, a true galaxy group, Hickson Compact Group 92, and will likely merge with each other. Radio observations in the early 1970s revealed a filament of emission between the galaxies in the group. This same region is also detected in the faint glow of ionized atoms seen in the visible part of the spectrum as a green arc. (Wikipedia)
The filament of gas and stellar material can be seen in this image surrounding NGC 7318 A/B at the center.
Capture info:
Location: SkyPi Remote Observatory, Pie Town NM US
Telescope: Officina Stellare RiDK 400mm
Camera: QHY 600M
Mount: Paramount MEII
Data: RGB 30 hours approximately.
Processing: Pixinsight