Barnard 175

Barnard 175 (B175) is a Bok globule shaped like a comet, situated roughly 400 parsecs away in the constellation Cepheus. It lies inside the Cepheus Flare shell, a vast assembly of molecular clouds. Its southern edge is lit by the star BD+69 1231, a B9.5V-type star, which creates Ced 201—a bright reflection nebula within B175.

Inside the globule, the only known Herbig-Haro object is HH 450, found within Ced 201. A feature once labeled HH 450X was first thought to be a knot but later identified as a background galaxy. The infrared source IRAS 22129+7000 also resides in Barnard 175.

The globule also hosts a supernova remnant called SN G110.3+11.3. This remnant is filamentary, with two red streaks named filament A and filament B. It is expected to soon collide head-on with the outflows from HH 450. The remnant moves at roughly 300 km/s, while the outflows travel at about 100 km/s, meaning the collision should occur in around 1,000 years.

When they meet, a fast radiative shock will envelop them, causing indentations in the remnant due to its lower density. Eventually, the remnant will push toward Barnard 175. Computer simulations suggest this event will dramatically change the globule’s shape and structure, potentially sparking new star formation.