Ou 1 (PNG 151.0-00.4) was discovered by Nicolas Outters in 2009 as he reviewed a narrowband image he had taken of NGC 1491 and noticed a faint spot. The object, along with several other PN candidates discovered by amateurs, was described in a 2012 paper which concluded that the object is likely an HII region, but left the ultimate determination to spectroscopic imaging of the potential central star. In a February 2022 note to the HASH database of planetary nebulae, Quentin Parker reported that the 10.4 meter Gran Telescopio Canarias has now done that spectroscopy, and concluded that the OIII and NII signatures and the presence of a blue central star (much too faint to show in my image) indicate that Ou 1 is indeed a PN.
The object clearly has an OIII signature, although it’s very faint and only surrounds the core region. In Ha, it also has a peculiar double tail somewhat reminiscent of HFG 1.
Full details on capture and processing are with the linked image.
Edited by astrovienna, 04 December 2022 - 10:23 PM.