NGC 1999 is a reflection nebula. A reflection nebula doesn’t emit light on its own. Much like fog around a lamp post, a reflection nebula shines because the light from an embedded source illuminates its dust. NGC 1999 lies close to the Orion Nebula in a region of our galaxy about 1,500 light-year away where new stars are being formed. NGC 1999 is lit by a bright, recently formed star, visible just left of center in this Hubble photo. the star’s white color is caused by its high surface temperature (about 10,000 °C, twice that of the Sun).
Image Credit: NASA