Astronomy:Messier 78
| Reflection nebula | |
|---|---|
 Image of Messier 78 captured using the Wide Field Imager camera on the MPG/ESO 2.2-metre telescope at the La Silla Observatory. | |
| Observation data: J2000.0 epoch | |
| Right ascension | 05h 46m 46.7s[1] |
| Declination | +00° 00′ 50″[1] |
| Distance | 1,350 ly (415 pc)[2] ly |
| Apparent magnitude (V) | 8.3[3] |
| Apparent dimensions (V) | 8′ × 6′[3] |
| Constellation | Orion |
| Physical characteristics | |
| Radius | 5 ly |
| Notable features | Part of the Orion complex |
| Designations | Ced 55u, DG 80, IRAS 05442-0000, [KPS2012] MWSC 0664, NGC 2068[1] |
Messier 78 or M78, also known as NGC 2068, is a reflection nebula in the constellation Orion. It was discovered by Pierre Méchain in 1780 and included by Charles Messier in his catalog of comet-like objects that same year.[4]
M78 is the brightest diffuse reflection nebula of a group of nebulae that includes NGC 2064, NGC 2067 and NGC 2071. This group belongs to the Orion B molecular cloud complex and is about 1,350 light-years distant from Earth.[2] M78 is easily found in small telescopes as a hazy patch and involves two stars of 10th and 11th magnitude. These two B-type stars, HD 38563 A and HD 38563 B, are responsible for making the cloud of dust in M78 visible by reflecting their light.[5]
The M78 cloud contains a cluster of stars that is visible in the infrared.[2] Due to gravity, the molecular gas in the nebula has fragmented into a hierarchy of clumps,[2] whose cores have masses ranging from 0.3 M☉ to 5 M☉.[6] About 45 variable stars of the T Tauri type,[7] young stars still in the process of formation, are members as well. Similarly, 17 Herbig–Haro objects are known in M78.[8]
Gallery
See also
References
- ↑ 1.0 1.1 1.2 "M 78". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=M+78.
- ↑ 2.0 2.1 2.2 2.3 Walker-Smith, S. L.; Richer, J. S.; Buckle, J. V.; Smith, R. J.; Greaves, J. S.; Bonnell, I. A. (March 2013), "The structure and kinematics of dense gas in NGC 2068", Monthly Notices of the Royal Astronomical Society 429 (4): 3252–3265, doi:10.1093/mnras/sts582, Bibcode: 2013MNRAS.429.3252W.
- ↑ 3.0 3.1 "Messier 78". https://messier.seds.org/m/m078.html.
- ↑ Frommert, Hartmut; Kronberg, Christine (9 October 2018), "Messier 78", SEDS Messier pages (Students for the Exploration and Development of Space (SEDS)), http://messier.seds.org/m/m078.html, retrieved 2018-12-05.
- ↑ Strom, S. E. et al. (July 1974), "Infrared and optical observations of Herbig-Haro objects.", The Astrophysical Journal 191: 111–142, doi:10.1086/152948, Bibcode: 1974ApJ...191..111S.
- ↑ Motte, F. et al. (June 2001), "A SCUBA survey of the NGC 2068/2071 protoclusters", Astronomy and Astrophysics 372 (3): L41–L44, doi:10.1051/0004-6361:20010543, Bibcode: 2001A&A...372L..41M.
- ↑ Herbig, G. H.; Kuhi, L. V. (February 1963), "Emission-Line Stars in the Region of NGC 2068", The Astrophysical Journal 137: 398, doi:10.1086/147519, Bibcode: 1963ApJ...137..398H.
- ↑ Zhao, Bing et al. (September 1999), "Newly Discovered Herbig-Haro Objects in the NGC 2068 and NGC 2071 Regions", The Astronomical Journal 118 (3): 1347–1353, doi:10.1086/301002, Bibcode: 1999AJ....118.1347Z.
External links
- Messier 78 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
- SEDS: Starforming Nebula M78
- NASA Astronomy Picture of the Day: M78: Stardust and Starlight (4 November 2005)
- NightSkyInfo.com – M78
- Astronomy Picture of the Day
- M78 Wide Field 2009 November 26
- M78 and Reflecting Dust Clouds in Orion 2010 March 2
- Haran, Brady; Haese, Paul. "M78 – Reflection Nebula". Deep Sky Videos. Nottingham Astronomy Group, University of Nottingham. http://www.deepskyvideos.com/videos/messier/M78_reflection_nebula.html.
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Coordinates: 
05h 46.7m 00s, +00° 03′ 00″
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