NGC 7027 — Planetary Nebula in Cygnus

NGC 7027 is one of the youngest known planetary nebulae, located in Cygnus about 3,000 light-years away, and one of the most-studied objects in stellar astrophysics. It is extremely compact — only about 14 arcseconds across — and dense, with a complex multi-shell structure that records a dramatic recent episode of mass loss. The central star, hidden behind a thick dust cocoon, has a surface temperature of around 200,000 K, among the hottest white dwarf progenitors known. NGC 7027 is so compact and bright that it serves as a calibration source across the radio, infrared, and optical spectrum and was one of the very first targets imaged with the James Webb Space Telescope.

A peculiar visual target. NGC 7027 looks essentially stellar in any small scope — an 8th-magnitude star that takes high magnification to reveal a tiny non-stellar disc. A 4-inch at 200x shows it as a slightly fuzzy point. An 8-inch at 300-400x resolves it cleanly into a small box-shaped disc with a hint of green-blue tint. A 12-inch reveals slight asymmetries in the disc. Without high magnification it is easy to walk right past. Star-hop from Nu Cygni about 1.5 degrees south. Best observed June through November.

Discovered by Édouard Stephan at Marseille in 1879 — the same Stephan whose name is on Stephan's Quintet. Its extremely young age — astronomers estimate it became visible as a planetary only about 600 years ago — has made it the gold standard for studying the very early stages of post-AGB stellar evolution.