Stephan's Quintet Trivia Questions

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

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

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

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

Webb's first deep field image in 2022 included SMACS 0723, not Stephan's Quintet, though the quintet was released separately.

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

While some members are at 290 million light-years, the foreground interloper is about 40 million light-years away, causing common confusion.

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