Westerhout 3
| Emission nebula | |
|---|---|
| H II region | |
Image of Westerhout 3 | |
| Observation data: J2000.0 epoch | |
| Right ascension | 02h 27m 4.1s |
| Declination | 61° 52′ 22″ |
| Distance | 7,000 ly (2,100 pc) |
| Constellation | Cassiopeia |
| Designations | W3, Fish Head Nebula |
Westerhout 3 (also known as W3) is a giant molecular cloud and a star-forming region in the Perseus Arm of the Milky Way Galaxy, first identified by the Dutch Astronmer Gart Westerhout. It is one of the most active sites of massive star formation in the outer parts of our galaxy, located in the constellation Cassiopeia at a distance of approximately 6,000 light-years from Earth. W3, with W4 and W5, forms part of the larger W3/W4/W5 complex, associated with the Heart and Soul Nebula, and corresponds specifically to the bright emission nebula Fish Head Nebula (IC 1795) within the Heart Nebula (Sh 2-190).
W3/W4/W4 complex in emission lines, as seen by the Northern Sky Narrowband Survey