NGC 2261 is Hubble's Variable Nebula in Monoceros.

The fan-shaped reflection nebula is made up of dust particles that reflect and scatter mostly blue light from the nearby star R Monocerotis, located in the tip of the nebula at bottom. The shape of the nebula varies over short time periods, believed to be caused by moving opaque clouds of dust and gas between the star and the nebula.

R Monocerotis itself is a massive young Herbig Ae/Be variable star that ranges in brightness from 10th to 13th magnitude.

The nebula was discovered by William Herschel in 1783. It lies 2,500 light-years away and is 2 x 4 arcminutes in apparent size.

It is named after astronomer Edwin Hubble who started studying the nebula in 1916 at Yerkes Observatory. In 1949, NGC 2261 was the subject of the first official photo taken with the new 200-inch Hale Telescope, taken by Edwin Hubble himself from the prime focus observing cage inside the top of the telescope on Mt. Palomar.

North is to the top in the above image.

NGC 2261 Catalogs: NGC 2261, Ced 83, LBN 920 Common Name: Hubble's Variable Nebula Object Type: Reflection Nebula Magnitude: 13.0v Size: 2' x 4' Constellation: Monoceros Image Field Centered At: RA: 06h 39m 12s Dec: +08° 45' 03"