Starless version here: https://astrob.in/sbo2yt/0/

Special thanks to @Göran Nilsson for identifying the Super Nova Remnant as HB3 or SNR G132.7+1.3.  There's not too many images of it out there, but it is a striking remnant.  I'm guessing it's overshadowed by the more glamorous heart and soul nearby.  

This is my first mosaic, and it was quite a project for me.  The mosaic itself is 2x2 panels imaged with Tak Epsilon 160ed and QHY600.  Data was collected in Ha, Sii and Oiii.  I had to spend more time on Oiii as the Ha (and even the Sii) signal was so overpowering.  I found a clever pixelmath equation on The Coldest Nights  website where channels were combined using a dynamic combination using Oiii as the reference.  It is really a remarkable technique, so check it out if you are looking for a new way to bring out the Oiii in a scene like this. 

Registering and stitching the mosaic together was another hurdle for me.  Pixinsight has put some work into developing new tools over the last couple of years, but all fell flat when trying to combine this data.  I think the large field of this scope and camera combo had just too much field distortion for it to succeed.  In the end I tried out APP, and it was brilliant.  It seamlessly combined the panels and registered each channel so that the data lined up just perfectly and had a neutral background.  When my trial runs out it's for sure a purchase!

There is just so much going on in this massive field.  It's a 7 x 4 degree field, at 1.46"/px resolution.  The final image is nearly 180 megapixels at relatively high resolution.  You can zoom in and see tons of amazing structures and details.  There is a lot of fainter and more diffuse nebula in this scene, which is why I shared it in starless as well as a version with stars.  You can find the starless version here: https://astrob.in/sbo2yt/0/

One thing that I found really interesting is that there is what appears to be a huge supernova remnant above and to the right of the Heart Nebula.  It has very nice filamentary detail in both Ha and Oiii.  The Oiii is very faint here, and I actually spent some extra time on this panel in Oiii to bring it out more.  I'm planning to reprocess just that panel at some point for the remnant, but my focus here was the two popular nebulae, Heart and Soul.  On a side note, I cant find any information about this remnant, if that is what it is, so if you know what it is called and have any links the details that would be greatly appreciated!

Captured using the Mach 2 GTO Unguided. 

As always, C&C is welcome.  Thanks for looking.