Nearby Nebulae

Optical or Visible Light

Look familiar? This view of the sky comes to us from the U.S. Naval Observatory in optical wavelengths - those that we see the everyday world in.  Because of all of the dust surrounding them, HII regions are nearly invisible to us in the optical.  Instead, we see the dust enshrouding them as dark regions on the sky.

Interactive answers

What are theyHII_Region_Basics.html
How do they expand in timeExpanding_HII_Region.html

Click to see the sky in different wavelengths

Rosette_Multistars.html
Orion_Blister_geometry.html

WWT

Explore the sky to see different HII regions