Deep Sky
Hubble's Variable Nebula

Constellation Monoceros
This is a variable nebula,  meaning it is a reflection nebula that changes its brightness because of the changes in their star brightness in this case, R Monocerotis.  NGC2261 is a classic example of a variable nebula. The 'fan' is approx 1 light-year across.  The nebula is approx 2500 light-years away from us. 
While it was discovered over 200 years ago, Edwin Hubble studdied it extensively and so it was named for him.