Discovery and Initial Investigation of a New Low Surface Brightness Planetary Nebula Candidate at High Galactic Latitude

ABSTRACT Planetary nebulae represent a late evolutionary phase of low‐ to intermediate‐mass stars. In this article, we present the serendipitous discovery of a previously unknown, faint potential Galactic planetary nebula (PN) in the constellation Camelopardalis, identified during a survey‐inspection, aiming at the detection of dwarf companions of the spiral galaxy NGC 2403. Narrow‐band imaging and spectroscopic observations of the nebula and its potential central star were obtained using a combination of amateur and professional telescopes. Our observations revealed a compact, dense, triangular structure—hereafter referred to as the Triangle Nebula—embedded within a broader elliptical region, which we call the Cam Nebula. Both are enclosed by an even fainter, nearly circular outer shell detectable only in deep, long‐exposure images. This Shell Nebula and the Cam Nebula may be superpositions by chance, but we will assume they are connected. We designate the entire complex as TBG‐N1. This is the first TBG nebula to avoid confusion with previously discovered TBG‐DWs (dwarf galaxies). A candidate for the central star was identified near the geometric centre of the outer shell. Spectroscopic analysis provided estimates of the nebular electron temperature and density. The combined evidence from imaging, spectroscopy, and the photometric properties of the central star candidate supports the classification of TBG‐N1 as a planetary nebula located at a distance of approximately 1 kpc. This discovery highlights the important role that collaborations between amateur and professional astronomers can play in uncovering and characterizing previously unrecognized celestial objects.