Discovered in 2011 by French amateur astronomer Nicolas Outters, Ou4, nicknamed the Giant Squid Nebula, is a remarkably faint bipolar outflow structure located in the constellation Cepheus. Stretching across more than two degrees of sky, its ghostly blue form resembles a deep-sea squid drifting through space. The nebula is likely powered by the triple-star system HR 8119, located near the apparent center of the outflow.

Ou4 lies within the larger and brighter emission nebula Sh2-129, also known as the Flying Bat Nebula. The deep red background is dominated by ionized hydrogen (Hα) emission, contrasting starkly with the OIII-rich, oxygen-emitting outflow that defines Ou4’s structure. The nature of the Giant Squid remains under study, with hypotheses ranging from a planetary nebula to a massive stellar wind structure formed by high-energy interactions in the central system.

This composite image features a captivating 2-panel mosaic of the intricate SH2-129 and OU4 nebulae, highlighting their stunning OIII-RGB emission patterns. Through the implementation of specialized filters, the mosaic vividly portrays the intricate interstellar structures and the distinct emission characteristics of these nebulae. SH2-129, also known as the Flying Bat Nebula, boasts dynamic filamentary features, while OU4, the Iris Nebula, exhibits intricate details and a captivating ring-like appearance. The utilization of the OIII-RGB technique enhances the contrast and color separation of the nebular components, providing valuable insights into the ionized gas dynamics and the underlying physical processes driving the evolution of these stellar nurseries.

Image Description and Details :

Barnard 150, also known as the Hippocampus Nebula, is a dark molecular cloud of dust in the constellation Cepheus located about 1,200 light years away.

This molecular cloud is part of our galaxy and it is one of 182 objects cataloged by astronomer Edward E. Barnard.On the right side of the image, we can see part of the squid nebula (OU4) (red signal).

Copyright: Thomas LELU