RCW 113: beautiful H II-region in Scorpius

RCW 113, also called Gum 55, is a huge H II-region in the constellation Scorpius, located in the neighboring Sagittarius Arm of the Milky Way.

Its core ionising open cluster NGC 6231 is part of a swath of young, bluish stars known as the Scorpius OB1 association. This Sco OB1 association contains star-forming areas with young, energetic stars of spectral class O & B.

In this field of view other interesting deep sky objects are visible.

The two bright stars to the left of NGC 6231 are zeta1 and zeta2 Scorpii.

The Prawn Nebula (upper right, with blue hues), also known as IC 4628, is an emission nebula around 6,000 light-years from Earth.

To the right of IC 4628 there is another open cluster NGC 6242.

The Wolf or Fenrir Nebula (SL-17), @ 10 o’clock position in this image, is a dark opaque nebula of dust and gas hiding the background stars.

The Dark Tower (SFO 82) is the prominent bright-rimmed cometary globule, about 1.5 degrees away from NGC 6231 and Zeta Scorpii. The shape of this massive structure of cosmic dust resembles a dark tower emerging from the star field background.

Most of these objects lie at a distance between 5,300-6,000 light-years from Earth.

Image acquired with AUS-2, data from 5 one-click observations.

Total integration time: 300 minutes

SHO: 10 sub-frames of 600s with each narrowband filter (SII, H-alpha and OIII).