This is the Dolphin Nebula, or Barnard 252:

This dark nebula is actually covers the whole image, with the darkest part being the dolphin itself. The rest of this dark nebula gives the entire image an orange cast – note that most of the stars in this image are tinted orange.

There’s not much information about this nebula, so its distance or when it was discovered are unknown.

This is a total of 80 minutes exposure using LRGB filters.

Note that there is another nebula called the Dolphin Nebula – and you can find it here.