NGC 1999 is a bright, albeit small, reflection nebula, located in the constellation Orion the Hunter. It lies approximately 1,500 light-years from the Earth. The nebula is illuminated by a young, pre-main sequence,star, designated V380 Orionis. This star's mass is approximately 3.5 times as large as that of our Sun. The nebula has a dark, triangular shaped, feature which is the object of much study, and some controversy. This dark feature, designated ‘Parsamian 34’, was originally considered to be a dense cloud of dust known as a ‘Bok Gloublar’. Recent studies, conducted by both space and ground based observatories, have indicated the feature is not a cloud of dust but is a hole, or empty cavity, in the surrounding nebula. The origin and driving force responsible for the formation of this void is uncertain and is a subject of speculation.
Two bright areas located directly below NGC 1999 are Herbig-Haro Objects. [HH-1 and HH-2] These represent the first of the HH objects recorded in the Herbig-Haro catalog. Although classified as 2 separate objects, HH-1 & HH-2 are actually produced by a single low mass proto-star hidden from view in a dark cloud of dust. These two HH objects are now considered to be the result of powerful jets of particles being ejected from an accretion disk surrounding the forming proto-star.
The image above is known as a mapped, or false, color image and was acquired using narrowband filters. It was assembled using the standard Hubble palette with SII mapped to Red, Ha mapped to Green and OIII mapped to Blue. The stars were overlaid with color data from a separate RGB image.