Instagram: @jeffreyhorne

This area of Cepheus doesn't get a lot of attention. There's no Elephant Trunk nebula, no Bat or Squid nebula, no Wizard nebula, no Iris Nebula...nothing that draws that much attention. So naturally, I wanted to take some time and get a really deep integration on it, to try for a unique view.

While I was planning a long integration, I didn't plan on going this long. I miscalculated the rising time of the target in the next image that I've planned (by a significant margin,) so I just kept adding data on this image until it was time to start the next one.

Maybe the most interesting thing in this photo is the small blue blob of Oiii (with a sharp Ha/Sii arc) that's about 20% over from the left side of the image, and about a third of the way up from the bottom. At some point during data acquisition, the Oiii just started showing up. I thought it was dust in my imaging train, but after re-taking my flats, the Oiii was still there. Jaša Rebula was able to figure out that the area had been cataloged as supernova remnant Te 12.

To my knowledge, supernova remnants are usually a bit more "wispy", and planetary nebulae are a bit more "blobby"...blobby like the Oiii that I imaged.

Jaša looked a little deeper and found that there wasn't Oiii noted for Te 12 in the HASH database:





Drew Evans then imaged it a longer focal length (1300mm with his SCA 260), to verify that the Oiii was present. Sure enough, it's there.



We also found a very hot white dwarf in the Oiii signal, so we think that Te 12 might be misclassified as a supernova remnant and might actually be a planetary nebula. On November 12, 2023, we submitted it to the relevant authorities for clarification and classification.

I've tried to email Phillip Teutsch (the namesake of Te 12) to let him know about this Oiii blob. I was able to find three different emails for him...two of which were undeliverable and one which hasn't replied to my email. I tried emailing a couple of his known colleagues as well, but nobody seems to have a current email address for him. If anyone knows how to get in touch with him, please let me know.

A BIG shoutout to Brian Fulda, Drew Evans, and Jaša Rebula for teaming up to figure out what this little blob of Oiii actually is. More to come from our little band of astronomy nerds!