The Shrimp Nebula, cataloged as Sharpless 2-188 and LBN 633, is a faint planetary nebula in the northern constellation Cassiopeia. With an apparent magnitude of 17.447, it ranks among the more demanding astrophotography targets and rewards only long, patient integration times. Its low surface brightness makes narrowband imaging with H-alpha and OIII filters essential to draw out its delicate, asymmetric shell structure. Under dark skies and with a sufficiently large aperture, deep exposures reveal the crescent-like arc that gives this object its distinctive shrimp-shaped appearance.
Names and Catalog numbers
- Shrimp Nebula
- Sh2-188 (Sharpless 188)
- LBN 633
Position and the cosmic neighborhood
The Shrimp Nebula lies at right ascension 01h 30m 33.18s and declination +58° 24′ 50.3″, placing it within the rich, star-studded region of Cassiopeia. This part of the sky sits along the northern Milky Way, so imagers will find the field crowded with faint background stars that can complicate stretching and background calibration. For northern-hemisphere astrophotographers Cassiopeia is circumpolar from many latitudes, giving generous windows of high-altitude imaging where atmospheric extinction is minimal. The dense stellar surroundings make careful framing and star reduction techniques worthwhile when processing the final image.
Nice to Know
- Its common name, the Shrimp Nebula, comes from the curved, crustacean-like arc that emerges only in deep exposures.
- At magnitude 17.447 it is exceptionally faint, making it a genuine challenge best suited to experienced deep-sky imagers.
- It carries the catalog designations Sharpless 2-188 and LBN 633, marking it in both emission-object and bright-nebula surveys.
- Situated roughly 3,640 light-years from Earth, it is a comparatively nearby planetary nebula within our own galactic neighborhood.
Brightness, distance and size
The object has an apparent magnitude of 17.4 mag, it lies about 3,640 light-years from Earth.
