Pickering’s Triangular Wisp is a faint portion on the Veil Nebula.
http://www.astropix.com/pickerings_triangular_wisp.html
Today, it would have been rightfully been called Fleming’s Triangular Wisp…
Click on the link to see a larger version with more information.
This is a composite of 160 minutes of narrowband hydrogen-alpha data combined with 180 minutes of RGB data.
Jerry