| Reflection nebula | |
|---|---|
| emission nebula | |
 NGC 2023 next to theHorsehead Nebula | |
| Observation data:J2000epoch | |
| Right ascension | 05h 41m 37.9s[1] |
| Declination | −02° 15′ 52″[1] |
| Distance | 1,300 ly (400 pc)[2] ly |
| Apparent dimensions (V) | 10'×10'[3] |
| Constellation | Orion[3] |
| Designations | NGC 2023,[3] LBN 954, IRAS 05391-0217[1] |
| See also:Lists of nebulae | |
NGC 2023 is anemission andreflection nebula in theequatorialconstellation ofOrion. It was discovered by theGerman-born astronomerWilliam Herschel on 6 January 1785. This reflection nebula is one of the largest in the sky,[4] with a size of10 × 10 arcminutes.[3] It is located at a distance of 1,300 ly (400 pc) from theSun, and is positioned~15′ to the northeast of theHorsehead Nebula.[2]
This star-forming nebula forms part of the Orion Bmolecular cloud,[2] orLynds 1630, and is located in the northern section of this complex. In terms ofstellar density, it is the poorest of the four clusters embedded in the cloud complex, with only 21 embeddedinfrared sources.[5] The reflection nebula is illuminated by theHerbig Ae/Be starHD 37903, which has aspectral class of about B2 Ve.[5] The region around the central star is radiating fluorescentmolecular hydrogen emission at a near-infrared range.[6][7] Infrared emission ofpolycyclic aromatic hydrocarbons has been detected from the nebula'sdust.[8]
