NGC 2170 is a complex reflection nebula embedded within a rich star forming region in the constellation Monoceros. Unlike emission nebulae that glow from ionized hydrogen, NGC 2170 shines primarily by reflected starlight, scattering the light of nearby young stars off fine interstellar dust. The soft blue and violet tones trace dust grains illuminated by hot stars, while pink and red regions reveal pockets of hydrogen gas energized by ultraviolet radiation. Dark, branching lanes of cold molecular dust cut sharply through the glow, marking dense regions where future stars may still be forming.

This field is part of the larger Monoceros molecular cloud complex, a dynamic environment shaped by stellar winds, radiation pressure, and gravity. The intricate contrast between luminous nebulae and opaque dust highlights the ongoing cycle of star birth and cloud erosion. Captured from Perth, Western Australia, this view preserves both the delicate color gradients and fine structural detail that make NGC 2170 a striking example of how starlight interacts with the raw material of the galaxy.

NGC 2170 is a dusty reflection nebula and stellar nursery that formed about 6 to 10 million years ago, located at the edge of the elliptically shaped, giant star-forming molecular cloud Monoceros, some 2,700 light-years away in the constellation of Monoceros.

NGC 2170 is specifically, the blue nebula in the bottom right quadrant of this image, this region ia approximately 15 light-years across and displays a mix of nebula types. The bluish section are reflection nebulae. The dust particle size in these areas reflects blue light. The reddish areas are emission nebulae, ultraviolet light from nearby stars lights the hydrogen and other gases in the nebula, which then emit light of their own in specific colors. Finally, what looks a bit like black ink spilled across the image are dark absorption nebulae, and are only seen because of the light that they block. In other words, the dark nebula is seen in silhouette.

Copyright: Albert Barr