A blog post about this object with more info and images.

The open cluster centered in this image is known as Melotte 15 . Melotte 15 is embedded within a central portion of the much larger glowing nebula identified as IC 1805.

The interesting structure in the center of the image is a giant area of hydrogen gas that is caused to glow by the intense ultraviolet radiation from the massive stars of the Melotte 15 star cluster.
Dust and gas clouds are twisted by the pressure of the intense radiation, the solar wind.
This formation is estimated to be 7,500 light years away from Earth, North is up.


Technical details:


Processing work flow:
Image acquisition, MaxiDL v5.07.
Stacked and calibrated in CCDStack2.
Levels, curves and color combine in PS CS3.


Optics, Meade LX200 GPS 12" @ f5
Camera, QHY9
Guiding, SXV-AO, an active optics unit, and Lodestar guide camera 8Hz
Image Scale, ~0,8 arc-seconds/pixel
45 x 1200s exposures for the H-alpha, emission of ionized Hydrogen = 15h
Narrowband cahnnels for ionized Oxygen and Sulfur are taken from an older wide field image seen above.