Sharpless 2-115 and 2-116: a

Image Title: Sharpless 2-115 and 2-116: a "downgraded" planetary nebula?

Date image was taken: August 23, 2023

Location: Schenectady, NY (USA)

Image Description and Details : 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.

Data for this image was collected during Summer 2023. Out of the 55 hours of collected data, close to 42 hours of data were used to generate this image. Data was pre-processed in Pixinsight, color mapping was performed in Photoshop according to modified SHO palette, and final image processing was completed in Pixinsight. RGB stars were used in place of narrowband stars.

Equipment Details: TS ONTC 10in f4 imaging Newtonian

AP 1100GTO-AE

QHY 268M

Astrodon 3nm Ha, SII, OIII filters and RGB color filters

Acquisition with SGP, APCC Pro, and PHD2

Processing with Pixinsight and Adobe Photoshop

Copyright: Luca Marinelli

Website or Facebook Profile: http://www.astrobin.com/users/lucam_astro/