Abell39
About this celestial object
Abell 39 appears as an almost perfect, delicate circle—a textbook planetary nebula.
Abell 39 in Hercules is noted for its nearly ideal spherical form; the shell of a sun-like star is expanding into space.
In a wide field the nebula has extremely low surface brightness—its geometric purity is precisely the appeal.
640 seconds total exposure sketch the fine ring only faintly, yet recognizably.
Image and observation
Catalogue: Abell39
Capture date: 2024-08-25
Total exposure: 640 s
Imaging and processing: Ulrich Schwarz · Vespera Pro