NGC 2174 (also known as Monkey Head Nebula) is an

H II An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundred ...

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 emissio ...

located in the constellation Orion and is associated with the open star cluster NGC 2175. It is thought to be located about 6,400 light-years away from

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

. The

nebula A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regio ...

may have formed through hierarchical collapse. There is some equivocation in the use of the identifiers NGC 2174 and NGC 2175. These may apply to the entire nebula, to its brightest knot, or to the star cluster it includes. '' Burnham's Celestial Handbook'' lists the entire nebula as 2174/2175 and does not mention the star cluster. The NGC Project (working from the original descriptive notes) assigns NGC 2174 to the prominent knot at J2000 , and NGC 2175 to the entire nebula, and by extension to the star cluster. Simbad uses NGC 2174 for the nebula and NGC 2175 for the star cluster. Glowing gas and dark dust do not survive well in the Monkey Head Nebula. Young stars near the center of the nebula generate stellar winds and high energy radiation that causes the nebula's material to shift into complex shapes. The nebula is primarily composed of hydrogen which glows at

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

wavelengths due to the radiation.

Hubble 24th Anniversary Images (2014)

Hubble Celebrates 24th Anniversary with Infrared Image of Nearby Star Factory (13225104285)

Gallery

File:PIA19836-NGC2174-MonkeyHeadNebula-IR-Spitzer-20150820.jpg, Infrared image of NGC 2174 as viewed by the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...

File:NGC-2174.tif, Monkey Head Nebula in Narrowband Sulfur-Hydrogen Alpha- Oxygen with a 1000mm telescope File:Monkey head H alpha 385mm stephan hamel wiki.jpg, Monkey Head Nebula in hydrogen alpha focal length 384mm File:Monkey Head Nebula bi-color Ha-OIII 384mm stephan hamel wiki.jpg, Monkey Head Nebula in bi-color with a 384mm telescope File:Monkeyhead nebula Nov 24.jpg, Monkeyhead nebula taken with a 140mm refractor by amateur astronomer Mark Johnston File:NGC2174 SHO Large06.jpg, NGC 2174 (Monkey Head Nebula) in SHO palette by W4SM, 17" PlaneWave CDK scope, Louisa, VA

References

External links

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Monkey Head Nebula at Constellation Guide

Monkey Head Nebula in the Staracle NGC catalog
{{Ngc25 H II regions Orion (constellation) 2174 Star-forming regions