Sh2-129, also known as Sharpless 129, is a designation used in astronomy to refer to a specific emission nebula in the night sky. The Sharpless catalog is a list of HII regions, which are areas of ionized gas where star formation is occurring.
Sh2-129 is located in the constellation Cepheus, a northern constellation. It's a region where new stars are forming, and it's characterized by ionized hydrogen gas, giving it a reddish appearance typical of many nebulae.
Astronomical objects like Sh2-129 are often studied and observed by astronomers to learn more about star formation, the lifecycle of stars, and the properties of interstellar gas and dust in our galaxy.
 

On 5 August 2023, while imaging the Bat nebula from Ollioules, a bright greenish streak appeared on the bottom right.
After checking each individual image captured (a total of 30 images, 5 minutes each were taken), I realized I had imaged a comet ... a quick internet check and I had a name, Comet C/2023 E1 (Atlas).
The animation below is done as a GIF of the 30 images taken