__NOTOC__ The Flame Nebula, designated as NGC 2024 and Sh2-277, is an

emission nebula An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. Among the several different types of emission n ...

in the constellation

Orion Orion may refer to: Common meanings * Orion (constellation), named after the mythical hunter * Orion (mythology), a hunter in Greek mythology Arts and media Fictional entities Characters and species * Orion (character), a DC Comics c ...

. It is about 1350

light-years A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by the International Astro ...

away. At that distance, the Flame Nebula lies within the Orion B cloud of the larger

Orion Molecular Cloud Complex The Orion molecular cloud complex (or, simply, the Orion complex) is a star-forming region with stellar ages ranging up to 12 Myr. Two Molecular cloud#Giant molecular clouds, giant molecular clouds are a part of it, Orion A and Orion B. The stars ...

. The bright star Alnitak (ζ Ori), the easternmost star in the Belt of Orion, appears very close to the Flame Nebula in the sky. But the star and nebula are not physically associated with one another. The Flame Nebula contains a young cluster of stars which includes at least one hot, luminous O-type star labeled IRS 2b. The dense gas and dust in the foreground of the nebula heavily obscures the star cluster inside the nebula, making studies at infrared wavelengths most useful. The energetic

ultraviolet light Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of th ...

emitted by the central O-type star IRS 2b into the Flame Nebula causes the gas to be excited and heated. The glow of the nebula results from the energy input from this central star. Within the nebula and surrounding the central hot star is a

cluster may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Cluster II (spacecraft), a European Space Agency mission to study the magnetosphere * Asteroid cluster, a small ...

of young, lower-mass stars, 86% of which have

circumstellar disk A Circumstellar disc (or circumstellar disk) is a torus, pancake or ring-shaped accretion disk of matter composed of gas, dust, planetesimals, asteroids, or collision fragments in orbit around a star. Around the youngest stars, they are the res ...

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

observations by the

Chandra X-ray Observatory The Chandra X-ray Observatory (CXO), previously known as the Advanced X-ray Astrophysics Facility (AXAF), is a Flagship-class space telescope launched aboard the during STS-93 by NASA on July 23, 1999. Chandra is sensitive to X-ray sources ...

show several hundred young stars, out of an estimated population of 800 stars. X-ray and infrared images indicate that the young stars are concentrated near the center of the cluster. Flame Nebula proplyds

The Flame Nebula was observed with

ALMA Alma or ALMA may refer to: Arts and entertainment * ''Alma'' (film), a 2009 Spanish short animated film * ''Alma'', an upcoming film by Sally Potter * ''Alma'' (Oswald de Andrade novel), 1922 * ''Alma'' (Le Clézio novel), 2017 * ''Alma'' ( ...

and this study found two populations, which are separated by a molecular cloud. The eastern population is 0.2-0.5 Myr old and has a disk fraction of 45±7%. The western population is slightly older at 1 Myr and has a lower disk fraction of 15±4%. This disk fraction is lower than the one observed in the mid-infrared, but the ALMA survey also observed a smaller region. The eastern part contains the O8 star IRS 2b and the western part contains the B0.5V star IRS 1. Hubble observations have shown that the Flame Nebula contains 4 clear

proplyds A proplyd, short for ionized protoplanetary disk, is an externally illuminated photoevaporating protoplanetary disk around a young star. Nearly 180 proplyds have been discovered in the Orion Nebula. Images of proplyds in other star-forming regio ...

and 4 candidate proplyds. Three of these are in the older western region and are pointing towards IRS 1. The other 5 are in the younger eastern region and are pointing towards IRS 2b.

Gallery

Image:Flame Nebula NGC 2024.jpg, Optical image in B, V and R filters, from

La Silla Observatory La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are also located at the site and are partly maintained by ESO. The observato ...

Image:Ngc2024 2mass.jpg, Infrared image, from

2MASS The Two Micron All-Sky Survey, or 2MASS, was an astronomical survey of the whole sky in infrared light. It took place between 1997 and 2001, in two different locations: at the U.S. Fred Lawrence Whipple Observatory on Mount Hopkins, Arizona, and ...

Image:The hidden fires of the Flame Nebula.jpg, Near-infrared image, from

VISTA Vista may refer to: Software *Windows Vista, the line of Microsoft Windows client operating systems released in 2006 and 2007 * VistA, (Veterans Health Information Systems and Technology Architecture) a medical records system of the United States ...

Image:Spectacular visible light wide-field view of region of Orion's Belt and the Flame Nebula.jpg, Visible light wide-field view of region of Orion's Belt and the Flame Nebula Image:NGC 2024 seen by the Chandra X-ray Observatory.jpg, NGC 2024 seen by the Chandra X-ray Observatory Image:The Flame Nebula.jpg, Flame Nebula and Horsehead Nebula Image:Horsehead and Flame Nebula.jpg, Horsehead and Flame Nebulae in H-alpha Image:NASA-FlameNebula-NGC2024-20140507.jpg, The Flame Nebula (NGC 2024) - based on Chandra X-Ray and Spitzer Infrared images

References

External links

* * * {{Sky, 05, 41, 54, -, 01, 51, 00, 1500 Orion molecular cloud complex NGC objects Orion (constellation) Emission nebulae Sharpless objects Gould Belt Star-forming regions