Squid Nebula Ou4

The Giant Squid Nebula, Ou4 and the Flying Bat Nebula, Sh2-129.

Seemingly completely surrounded by the reddish hydrogen emission region SH2-129, the true distance and nature of the Squid Nebula have been difficult to determine. A recent investigation suggests Ou4 is actually located within SH2-129 which is around 2,300 light-years away from the solar system. If this is the case then Ou4 would represent a spectacular outflow driven by HR8119, a triple system of hot, massive stars seen near the centre of the nebula. If so, the truly giant Squid Nebula would physically be nearly 50 light-years across.

I assigned the SII data to be more of a magenta tone (more extreme red if you will) in order to differentiate it from the Ha data in red.