Stephan's Quintet Trivia Questions

Édouard Stephan first observed the quintet at the Marseille Observatory, making it the first compact galaxy group ever identified.

The combined magnitude is around 13, far too dim for naked-eye viewing; a moderate telescope is needed to resolve the group.

Only four are bound; the fifth is a foreground galaxy not interacting. The bound four are indeed merging over billions of years.

On July 12, 2022, NASA released JWST's first set of scientific images, including Stephan's Quintet, making it one of the earliest publicly shared targets.

The fifth galaxy, NGC 7320, is a foreground interloper about seven times closer to Earth, not part of the tight group.

One member, NGC 7319, harbors an active galactic nucleus with radio jets, revealed by X-ray and radio observations.

Several other compact groups, like Hickson 90, also contain foreground interlopers; it's not unique.

The four interacting galaxies of Stephan's Quintet are about 290 million light-years away. Only NGC 7320, a foreground galaxy, is 40 million light-years away, so the quintet as a whole is not at that distance.