B33

E557732

B33 is the catalog designation for the Horsehead Nebula, a dark molecular cloud in the constellation Orion whose distinctive silhouette resembles a horse’s head.

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Statements (46)

Predicate Object
instanceOf dark nebula
molecular cloud
alsoKnownAs Horsehead Nebula NERFINISHED
angularSize approximately 8 arcminutes by 6 arcminutes
appearsIn Orion’s Belt region NERFINISHED
backlitBy IC 434 NERFINISHED
bestSeenFrom dark-sky sites
bestSeenWith long-exposure astrophotography
cataloguedBy Edward Emerson Barnard NERFINISHED
catalogueEntryNumber 33
composedPrimarilyOf molecular hydrogen
contains cold gas
dust
declination −02° 27′ 30″
distanceFromEarth approximately 1375 light-years
approximately 420 parsecs
hasApparentMagnitude approximately 6.8 (region as a whole)
hasCatalogDesignation B33
hasDensity higher than surrounding IC 434 region
hasFeature bright rim on side facing ionizing radiation
dense pillar-like structure
hasSilhouetteShape horse’s head
hasStructure clumpy and filamentary gas
ionizedBy nearby massive stars in Orion OB1 association
isDarkAgainst emission nebula IC 434 NERFINISHED
isIconicFor its horsehead-shaped silhouette in astrophotography
isSiteOf ongoing star formation
liesIn Milky Way galaxy NERFINISHED
Orion Arm of the Milky Way NERFINISHED
locatedIn Orion Molecular Cloud Complex NERFINISHED
locatedInConstellation Orion NERFINISHED
near Flame Nebula NGC 2024 NERFINISHED
bright star Alnitak
reflection nebula NGC 2023 NERFINISHED
obscures background H-alpha emission
observedBy Hubble Space Telescope NERFINISHED
Submillimeter and radio observatories
Very Large Telescope NERFINISHED
observedIn Barnard Catalogue of Dark Markings in the Sky NERFINISHED
partOf Orion B molecular cloud NERFINISHED
rightAscension 05h 40m 59s
spectralFeaturesInclude molecular lines such as CO
temperature about 10 Kelvin in densest regions
visibleIn infrared wavelengths
optical wavelengths
radio wavelengths

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.