De Mairan’s Nebula, cataloged as Messier 43 and NGC 1982, is a compact emission nebula that forms part of the sprawling star-forming complex in Orion. In astrophotography it is often captured together with its far more famous neighbor, appearing as a rounded glowing patch separated from the larger nebulosity by a dark lane of obscuring dust. Its bright core responds well to narrowband filters, particularly hydrogen-alpha, which brings out the delicate structure surrounding its illuminating star. Because it sits within one of the sky’s most photographed regions, it is an accessible target for imagers of nearly every skill level and equipment class.
Names and Catalog numbers
- De Mairan's Nebula
- M 43 (Messier 43)
- NGC 1982
Position and the cosmic neighborhood
De Mairan’s Nebula lies in the constellation Orion at a right ascension of 05h 35m 31s and a declination of -05° 16′ 12″, placing it squarely within the rich Orion star-forming region. It shares this crowded stretch of sky with the towering nebulosity of its larger companion, from which it is visually divided by a prominent dark dust lane that makes for a striking compositional element in wide-field images. The surrounding field is dense with young stars and glowing gas, so framing De Mairan’s Nebula almost inevitably captures a swath of the greater complex in the same shot. For imagers, this neighborhood offers a wealth of contrast between bright emission and shadowy dust that rewards careful exposure planning.
Nice to Know
- De Mairan’s Nebula carries two catalog identities: Messier 43 and NGC 1982.
- It is a distinct emission nebula that is frequently mistaken as merely part of its brighter neighbor in Orion.
- A conspicuous dark dust lane visually separates it from the surrounding nebulosity, giving it a rounded, self-contained appearance in photographs.
- Its position in Orion makes it best observed in mid December, when it culminates at astronomical midnight.
