Barnard 43 is a dark nebula in Ophiuchus. There. Now you know everything about Barnard 43 that I do. I wasn’t able to find any reference data on it.

Dark Nebula are regions where dust clouds block the light of the stars behind them. They aren’t truly dark and in this image the “dark dust” is actually a lighter gray but you can tell the relative density of the clouds by the brightness of the stars shining through. The stars appears smaller and dimmer where the dust is denser.

Most of the stars in this field appear to be behind the dust though that’s not directly obvious. However, dust tends to redden the light of whatever is shining through it and these stars are all reddish. It’s much like the dust in our atmosphere makes sunsets look redder. The blue light gets scattered by the dust allowing the red to shine through.

This is 32h 45m of LRGB data. You can find the processing details at astrobin.