Messier 78


For other uses, see M78 (disambiguation).





















M78
Reflection nebula

Messier 78.jpg
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]
Distance1,350 ly (415 pc)[2] ly

Apparent magnitude (V)
8.3
Apparent dimensions (V)
8′ × 6′
ConstellationOrion
Physical characteristics
Radius5 ly
Notable featuresPart of the Orion Complex
DesignationsCed 55u, DG 80, IRAS 05442-0000, [KPS2012] MWSC 0664, NGC 2068[1]
See also: Lists of nebulae

Messier 78 or M 78, 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.[3]


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.[4]


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] the denser cores of which about to form stars with masses of up to 7030994275000000000♠5 M☉.[5] About 45 variable stars of the T Tauri type,[6] young stars still in the process of formation as well as some 17[7]Herbig–Haro objects are known in M78.




Contents





  • 1 Gallery


  • 2 See also


  • 3 References


  • 4 External links




Gallery





  • VISTA image of Messier 78.







  • Spitzer image of Messier 78.





See also


  • Messier 78 in fiction


References




  1. ^ abc "M 78". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-02-14..mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"""""""'""'".mw-parser-output .citation .cs1-lock-free abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .citation .cs1-lock-registration abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .citation .cs1-lock-subscription abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolor:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-ws-icon abackground:url("//upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Wikisource-logo.svg/12px-Wikisource-logo.svg.png")no-repeat;background-position:right .1em center.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:inherit;padding:inherit.mw-parser-output .cs1-hidden-errordisplay:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintdisplay:none;color:#33aa33;margin-left:0.3em.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em


  2. ^ abcd 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, arXiv:1212.2018, Bibcode:2013MNRAS.429.3252W, doi:10.1093/mnras/sts582.


  3. ^ Frommert, Hartmut; Kronberg, Christine (October 9, 2018), "Messier 78", SEDS Messier pages, Students for the Exploration and Development of Space (SEDS), retrieved 2018-12-05.


  4. ^ Strom, S. E.; et al. (July 1974), "Infrared and optical observations of Herbig-Haro objects.", Astrophysical Journal, 191: 111–142, Bibcode:1974ApJ...191..111S, doi:10.1086/152948.


  5. ^ Motte, F.; et al. (June 2001), "A SCUBA survey of the NGC 2068/2071 protoclusters", Astronomy and Astrophysics, 372 (3): L41–L44, arXiv:astro-ph/0105019, Bibcode:2001A&A...372L..41M, doi:10.1051/0004-6361:20010543.


  6. ^ Herbig, G. H.; Kuhi, L. V. (February 1963), "Emission-Line Stars in the Region of NGC 2068", Astrophysical Journal, 137: 398, Bibcode:1963ApJ...137..398H, doi:10.1086/147519.


  7. ^ 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, Bibcode:1999AJ....118.1347Z, doi:10.1086/301002.




External links






  • Messier 78 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

  • 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



  • Haese, Paul. "M78 – Reflection Nebula". Deep Space Videos. Brady Haran. Missing or empty |url= (help)

Coordinates: Sky map05h 46.7m 00s, +00° 03′ 00″









-

這個網誌中的熱門文章

How to read a connectionString WITH PROVIDER in .NET Core?

圖片
6 I added .AddJsonFile("Connections.json", optional: true, reloadOnChange: true) in public Startup(IHostingEnvironment env) Connections.json contains: "ConnectionStrings": "DefaultConnection": "Server=(localdb)\mssqllocaldb;Database=DATABASE;Trusted_Connection=True;MultipleActiveResultSets=true", "COR-W81-101": "Data Source=DATASOURCE;Initial Catalog=P61_CAFM_Basic;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", "COR-W81-100": "Data Source=DATASOURCE;Initial Catalog=Post_PS;User Id=USERID;Password=PASSWORD;Persist Security Info=False;MultipleActiveResultSets=False;Packet Size=4096;", "MSEDGEWIN10": "Data Source=DATASOURCE; Initial Catalog=COR_Basic; Persist Security Info=False;Integrated Security=true;MultipleActiveResultSets=False;Packet Size=4096;Application Name="COR_Basic"", "server...
閱讀完整內容

Node.js Script on GitHub Pages or Amazon S3

圖片
0 I'm wondering if I can run a Node.js script in my Jekyll page from GitHub Pages or Amazon S3? I think it can't run on GitHub Pages since it doesn't support server side code. Not too sure. The code is below: var Airtable = require('airtable'); var base = new Airtable(apiKey: 'YOUR_API_KEY').base('appAnZVyYqusNPV5Q'); base('Invitee list').select( // Selecting the first 3 records in Complete list: maxRecords: 3, view: "Complete list" ).eachPage(function page(records, fetchNextPage) // This function (`page`) will get called for each page of records. records.forEach(function(record) console.log('Retrieved', record.get('Email')); ); // To fetch the next page of records, call `fetchNextPage`. // If there are more records, `page` will get called again. // If there are no more records, `done` will get called. fetchNextPage(); , function done(err) if (err) console.error(err); return; ); node.js ...
閱讀完整內容

Museum of Modern and Contemporary Art of Trento and Rovereto

圖片
Art museum in Rovereto TN, Italy Museum of Modern and Contemporary Art of Trento and Rovereto Museo d'arte moderna e contemporanea di Trento e Rovereto MART, Entrance Location Corso Angelo Bettini, 43, 38068 Rovereto TN, Italy Coordinates 45°53′38″N 11°02′42″E  /  45.8940°N 11.0450°E  / 45.8940; 11.0450 Coordinates: 45°53′38″N 11°02′42″E  /  45.8940°N 11.0450°E  / 45.8940; 11.0450 Type Art museum Director Gianfranco Maraniello Public transit access Trento train station. Taxis outside station. Website mart.trento.it The Museum of Modern and Contemporary Art of Trento and Rovereto (MART) ( Museo d'Arte Moderna e Contemporanea di Trento e Rovereto , in Italian) is a museum centre in the Italian province of Trento. The main site is in Rovereto, and contains mostly modern and contemporary artworks, including works from renowned Giorgio Morandi, Giorgio de...
閱讀完整內容