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2023, September 2023 Charles Lillo 2023, September 2023 Charles Lillo

Sharpless 2-115 and 2-116: a

Sharpless 2-115 is an emission nebula just North and West of Deneb, in the constellation Cygnus. It displays a chaotic morphology of gas emissions and dark nebulae. In the relatively high-resolution image presented here, pillars and Bok globules can be readily identified. Adjacent to Sh2-115 is a round structure originally cataloged as a planetary nebula. Sh2-116 was included in the assigned the catalog number Abell 71 in 1966 and hypothesized to be a planetary nebula by Perek and Kohoutec in 1967 (Perek, L. & Kohoutek, L. 1967, Catalogue of Galactic Planetary

Nebulae) . A morphological study by Pismis, Hasse, and Quintero in 1991 (https://iopscience.iop.org/article/10.1086/132891) reclassified Abell 71/Sh2-116 as an HII region. In their study, Pismis et al claimed that a reason for the reclassification was lack of OIII signal. In the image presented here, as well as other amateur images, OIII in Sh2-116 is clearly present, which leads to question the conclusions of the 1991 study.

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