The New Horizon Team (NHZ) is happy to present a first image of a newly detected Halo around the Planetary nebula [url=https://simbad.cds.unistra.fr/simbad/sim-id?Ident=%40896647&Name=PN%20A66%20%20%2015&submit=submit]PN A66 15[/url], also called Abell 15. Abell 15 is a small, only 36.6 arcsec in diameter Planetary nebula located in Canis Major.  Our team, under the lead of [url=https://www.astrobin.com/users/xSky_Watcher/]Tim Schaeffer[/url] focuses on finding new objects in our nightsky or on photographing unknown things, discovered this Halo in a Ha survey. As it was rather easily visible in the survey we weren't sure if anyone else has imaged/detected it yet and after doing some research we found that there is no image of it out there which suggested that we were the first ones to pick it up - spoiler alert, we weren't.  After chatting with a friend, [url=https://www.astrobin.com/users/AstroChe/]Chester Hall-Fernandez[/url]  about ongoing projects we found out that he also detected this structure 2 years prior in a widefield shot of his (See revision B). Funnily enough this is the second time our Team's and Chester (+friends) stumbled upon the same object, just like we did with the [url=https://www.astrobin.com/b9kfaf/]Lightling Bolt Nebula[/url]. As we stumbled upon this same object but Chester never finished an image, we decided to team up for this post to collectively share this new discovery and involve all parties.  Funnily enough, it doesn't stop here - chatting with [url=https://www.astrobin.com/users/Marcel_Drechsler/]Marcel Drechsler[/url] it turns out that he also noticed the object in a survey a year or so prior to us picking it up. Going further still, I also mentioned the Halo to another friend, Sakib Rasool who it turns out detected the structure way back in 2017 and knows someone who detected it way back in 2001 - more on that in the text below. Knowing all of this we should really take a moment and appreciate what Amateur Astrophotography has become, not only can we follow our passion and produce nice images, but also possibly discover new objects in our nightsky. The fact that this Halo in particular has been discovered by *at least* 4 people between 2017 and 2023 truly is a testament of the way our hobby has evolved and to what doors are open to us, with modest equipment in the backyard or in a remote site.  As no one ever finished (or started) an image and we were in the midst of doing exactly that, our team carried on to produce a deep comprehensive image of the region around Abell 15. In the end we ended up with around 70h of data total. Part of this image in particular was [url=https://www.astrobin.com/users/DrKrud/]Logan Carpenter[/url], [url=https://www.astrobin.com/users/bsteeve/]Steeve Body[/url] and [url=https://www.astrobin.com/users/keno/]Ken Hall[/url] . As Ken was shooting Ha and Oiii with his 11" RASA and captured the vast majority of the data we decided to take his Ha and Oiii data as Standalone for this image. Logan and Steeve also got data and we decided to use Logan's data for RGB stars and galaxies as well as continuum subtraction. After getting all of the data, our editor and photograph Steeve produced the fantastic image you see in this post - big thank you to him and his continued effort to get the best out of our data. We hope you enjoy this image and the small backstory. We also have some major projects in the workings/finishing up so can't wait to share those!  The NHZ Team - Text written by Tim *** Extra text from Sakib "Abell 15 is one of the lesser known of the Abell planetary nebulae and has received very little attention from astrophotographers. However this deep ~70 hour exposure image reveals a very unknown discovery for the first time, an outer halo measuring approximately 20 arcminutes surrounding the already known 36 arcsecond central core. This outer halo was initially discovered by the professional astronomer Peter McCullough in 2001 after analysing data from the SHASSA survey. It was also independently discovered by the Galactic Planetary Nebula Halo Survey (GPNHS) team in 2017 after being serendipitously identified on DSS, SHASSA, Finkbeiner atlas and the MDW Sky Survey plates. On later occasions, it has been independently discovered by the New Horizons Team and Chester Fernandez in 2024 and also by Marcel Drechsler. Haloes have been identified around many planetary nebulae with the majority having being discovered by professional astronomers as part of systematic searches. However in the past decade, amateur astrophotographers have made new discoveries due to much longer narrowband exposures. Other projects such as the Galactic Planetary Nebula Halo Survey (led by the amateur astronomer Sakib Rasool) search for extremely faint outer haloes by checking archival sky survey data and getting them verified photographically. The majority of haloes identified surrounding planetary nebulae represent a post main sequence phase of the stellar evolution of low and intermediate mass stars (0.8-8 masses) known as the asymptotic giant branch (AGB). This name refers to an evolutionary track on the Hertzsprung-Russell diagram, which is a tool used by professional astronomers to show the relationship between stellar luminosity and temperature. The AGB phase precedes the formation of a planetary nebula from a low mass star that has begun to deplete its fuel for nuclear fusion. Winds blow the outer layers and some of this mass loss ejecta forms a photoionized shell of material around the remnant core. This is referred to as an AGB halo. Examples include the well known halo around NGC 6543 and there are countless others such as M97. According to professional studies, it is purported that 60% of elliptical and spherical planetary nebulae are surrounded by an AGB halo. Very few happen to have a double halo such as M57, NGC 2438 and the lesser known halo around NGC 2867. However some haloes identified around a small population of planetary nebulae don't represent previous mass loss ejected by the central star. They are large clouds of unrelated material belonging to the surrounding interstellar medium that happen to be ionized and made to glow by the ultraviolet radiation of the central star leaking out of the optically thin planetary nebula shell. These so-called "ISM haloes" have been identified around a number of planetary nebulae such as HDW 2 (Sh2-200) and also MWP 1, which has a 1 degree OIII structure surrounding it discovered by the professional astronomer David Frew. Some such as NGC 3242, NGC 6751 and NGC 6894 possess both an inner AGB halo and an outer ISM structure. Due to its large angular size in comparison to the central core, the large structure surrounding Abell 15 is very likely to be ionized ISM. Other facts that support this conclusion are the irregular shape of this outer halo and an enhanced density of material towards the part facing the side of Abell 15 that exhibits outer limb brightening. This is indicative of both Abell 15 and its central star moving through space and the ionizing radiation causing an ambient ISM cloud to glow."