First discovered in 1786 by Wilhelm Herschel, NGC 2024 (Flame Nebula) is an emission nebula located in the constellation Orion. Located directly adjacent to the star Alnitak (Zeta Orionis), the easternmost star of Orion's belt, it is easily observed by even small telescopes due to its relatively large size. A young, massive star located somewhere within the nebula shines energetic light into the great hydrogen clouds there, stripping the atoms of their electrons. We see this beautiful firey glow when the ionized hydrogen atoms and the electrons recombine. It was previously thought that Alnitak was the source of this ionizing energy, however researchers (Bik et al., see below) have proposed the source of this light as IRS2b, the hottest and most luminous star within the obscured region of the nebula.
The dark lane that runs up the middle of the nebula is actually a large cloud of dust that obscures the visible light from the interior of the nebula's "star nursery." The central cluster can, however, be seen at infrared wavelengths (see link below). The bright blue "daggers" seen in the bottom-right corner of the image are camera artifacts produced by bright light from Alnitak, which saturates a large part of the image. The Flame Nebula has an estimated angular diameter of 14 x 17 arcminutes and is located at about 1500 light-years away. This means the nebula is 7.4 light-years tall x 6.1 light-years wide!
Bennett, Jeffrey, Megan Donahue, Nicholas Schneider, and Mark Voit. The Cosmic Perspective. 6th ed. San Francisco: Addison-Wesley, 2010. 594-595.
Bik, Arjan et al. Identification of the ionizing source of NGC 2024. Accessed 6 Dec. 2010. <http://arxiv.org/abs/astro-ph/0303029>.
Block, Adam. "Flame Nebula Close-up."Astronomy Picture of the Day. Accessed 6 Dec. 2010. <http://antwrp.gsfc.nasa.gov/apod/ap101126.html>.
Emerson, J. "The Flame Nebula in Infrared." Astronomy Picture of the Day. Accessed 6 Dec. 2010. <http://antwrp.gsfc.nasa.gov/apod/ap100112.html>.
|Right Ascension (J2000)||05:41:54|
|Filters used||blue(B), green(V), red(R), and clear(C)|
|Exposure time per filter||60 seconds in C, 300 seconds in BVR|
5, 2010 (C)