A reflection nebula in Monoceros, also known as NGC 2261, which is illuminated by the irregular variable R Monocerotis. The nebula's variability was detected by E. P. Hubble in 1916 and probably arises from changes in the star's luminosity and shadowing by dense clouds within the nebula. R Monocerotis is a young T Tauri star and a strong infrared source. It exhibits a vigorous outflow, and is apparently surrounded by a protoplanetary disk—a disk of material from which planets may form.
Subjects: Astronomy and Astrophysics.