De Mairan's Nebula, part of Orion Nebula
|Rektascenzija||05 : 35.6 (u:m)
|Deklinacija||-05 : 16 (sto:m)
|Razdalja||1.6 (*1000 sv.l.)
|Vizual. magnituda||9.0 (mag)
|Zorni kot||20x15 (loc min)
M43 is actually a part of the Great Orion Nebula, M42, which is separated from the main nebula by an impressive, turbulent dark lane. It was first reported by de Mairan in 1733 as a "brilliance surrounding a star" which he thought was "very similar to the atmosphere of our Sun, if it were dense enough and extensive enough to be visible in telescopes at a similar distance". Charles Messier included in his fine drawing of the Orion Nebula, and assigned it an extra catalog number. Moreover, William Herschel took it into his list with the number H III.1, although normally he careful avoided to assign his numbers to Messier objects.
The diffuse nebula M43 surrounds the irregular young "nebula variable" NU Orionis (HD 37061, attn: Not "nu Orionis") of magnitude 6.5-7.6 and spectral type BIV. It seems that M43 is excited to shine by this star, and contains its own, separate small cluster of stars which have formed in this part of the Orion nebula.
The dark features along its eastern border are well visible in telescopes starting at about 8 inch. The nebula itself is a fine view even in a 4-inch. Alister Ling in his recent review of observing the Orion nebula with filters (Astronomy, December 1995 issue), mentions the Comma shape of this nebula.
Bill Arnett's Orion Nebula M42/43