While the series of photos to image the Flame Nebula or NGC 2024 take only a few seconds each to expose finding, identifying, and verifying the nebula take hours of telescope time. Tilt the image above back and forth about the long axis to visualize the nebula.
NGC 2024, in the image directly above, stands out in a single 30″ exposure (at ISO12,800 f/9.5 FL2350mm). A hint of its multi-coloured array of emission gases is seen here. It is an emission nebula between Al nitak in Orion’s Belt and V1197Orionis, the K4 III red giant to the left or West in this image, with patches of nebulae cut by dark bands and threads. A broad dust lane travels the full width of the nebula. At least a dozen stars of high magnitude are embedded in the nebula.
The Flame Nebula has been estimated to be only 900 light-years away from Earth, and is part of the Orion Molecular Complex, a star-forming region. The nebula is ionized and made to luminesce by the easternmost star in Orion’s Belt, Alnitak (ζ Ori). The Flame Nebula glows in a variety of colors, from yellow to orange, though the predominant hue is shell-pink.
The Orion star formation molecular complex is the nearest region to Earth of on-going star formation that continues to produce both low and high mass stars. It is made up of two principal regions: Orion B, of which the NGC 2024 is the upper (northern) edge, and Orion A, the lower (southern) edge, ending in the Orion Nebula, M 42. Until recently, principal studies of the complex have been undertaken from the radio signal of J = 0-> 1 rotational levels of 12CO. Molecules detected in the Orion B region now include other simple species such as CS, SiO, HCN, HCO+, and complex O- and N-bearing species with 6 or more atoms such as methanol (CH3OH), acetone (CH3)2CO or ethanol (CH3CH2OH), and less known species such as methyl formate (HCOOCH3), acetonitrile (CH3CN), ethyl cyanide (C2H5CN).
Prof. Dr. John Bally, Department of Astrophysical and Planetary Sciences, University of Colorado at Boulder has reported,
“The 100 Myr-old Orion complex is located on the far side of the Gould’s Belt system of clouds and young stars through which our Solar system is drifting. Over the last 12 Myr, Orion has given birth to at least ten thousand stars contained in a half dozen sub-groups and short-lived clusters. The Orion OB association has been the source of several massive, high-velocity run-away stars, including mu-Columbae and AE Aurigae. Some of Orion’s most massive members died in supernova explosions that created the 300 pc diameter Orion / Eridanus super-bubble whose near wall may be as close as 180 pc. The combined effects of UV radiation, stellar winds, and supernovae have impacted surviving molecular clouds in Orion. The large Orion A, IC 2118 molecular clouds and dozens of smaller clouds strewn throughout the interior of the superbubble have cometary shapes pointing back towards the center of the Orion OB association. Most are forming stars in the compressed layers facing the bubble interior.” Bally, John “Overview of the Orion Complex”, arXiv:0812.0046v1 (2008)