Cone Nebula — The Cone Nebula is a famous nebula in the Orion Arm surrounding the NGC 2264 star cluster.
The ‘cone’ is a triangular dark nebula near the bottom of the nebula. The bright star at the centre of this picture is 15 Monocerotis (or ‘S Monocerotis’) – it is a quadruple star system consisting of four brilliant blue-white stars (classes O7, B7, B8 and A6) and it is partly responsible for causing the nebula to glow.
The distance to the Cone Nebula is well-known, because it has a cluster of stars at the centre of it. The distance is about 2200 light years which means the nebula is within the Orion Arm about 900 light years further from us than the Orion Nebula.