M43 · De Mairan's Nebula
| Chinese name | 德梅伦星云 |
|---|---|
| Type | Emission nebula |
| Constellation | Ori |
| RA | 05h35m |
| Dec | −05° |
| Apparent magnitude | 9ᵐ |
| Hemisphere | Both hemispheres |
| Best season | Winter |
| Difficulty | Moderate |
| Focal length | 中焦 400–800mm |
About
M43, De Mairan's Nebula, is a distinct emission nebula north of the Orion Nebula, separated from M42 by a dark dust lane and lying about 1,340 light-years away within the same Orion complex. Discovered by the 18th-century French astronomer De Mairan, it forms a comma-shaped arc around the young star NU Orionis. Though usually overshadowed by the far brighter M42, it is an active star-forming region in its own right. Its colors are as rich as M42's, glowing in pink-red and teal. When imaging the Orion Nebula, it is an essential part of the composition.