{"id":9050,"date":"2020-11-19T15:14:38","date_gmt":"2020-11-19T14:14:38","guid":{"rendered":"http:\/\/outters.fr\/?p=9050"},"modified":"2025-07-15T17:04:05","modified_gmt":"2025-07-15T16:04:05","slug":"m74-lrvb","status":"publish","type":"post","link":"https:\/\/www.outters.fr\/?p=9050","title":{"rendered":"M74 Lrvb"},"content":{"rendered":"

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M74 Lrvb
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Image Lrgb<\/h2><\/a><\/div><\/div><\/div>
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Commentaires sur l’objet photographi\u00e9<\/span><\/p><\/h1><\/span>

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\"outters-nicolas\"<\/p>\n

Pour une fois c’est un Messier mais pas si facile que cela. Traitement d\u00e9licat pour faire ressortir les nuances de couleurs.<\/p>\n

Objet assez bas sur l’horizon donc acquisitions pas si \u00e9videntes avec la m\u00e9t\u00e9o.<\/p>\n<\/div><\/div><\/div><\/div><\/div>

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Donn\u00e9es techniques
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Donn\u00e9es techniques de prise de vue<\/h2><\/div>
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Object : M74
\nCommon name :
\nDate images Du 5 au 19 novembre 2020
\nOptics : Rcos 12.5″
\nMount : Paramount ME Num\u00e9ro 3
\nLocation : Sirene observatory
\nSeeing : fwhm : 1.7 \u00e0 3.4
\nCcd : Apogee 16U
\nfilter wheel : Apogee
\nfilters : Astrodon
\nL rvb
\nFocuser :TIM
\nGuiding : Atik 314L+
\nTemp. out : T\u00b0 2 \u00e0 5.3\u00b0
\nTemp ccd : -25\u00b0
\nResolution …………… 0.647 arcsec\/px
\nRotation …………….. -86.404 deg (flipped)
\nObservation start time … 2020-11-16 21:24:24 UTC
\nObservation end time ….. 2020-11-16 21:39:24 UTC
\nGeodetic coordinates ….. 5 29 13 W 44 00 00 N 1100 m
\nFocal distance ……….. 2870.07 mm
\nPixel size …………… 9.00 um
\nField of view ………… 44′ 9.3″ x 44′ 9.3″
\nImage center …………. RA: 1 36 41.774 Dec: +15 47 01.27
\nTotal exposure :\u00a0 19.33 h
\ntout en binning 1×1
\nRouge 40 x 5′ \/ vert 35 x 5′ \/ bleu 40 x 5′
\nL : 61 x 15′<\/div><\/div><\/div>
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Donn\u00e9es scientifiques<\/h2><\/div>
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Source wikipedia<\/p>\n

M74<\/b>\u00a0(NGC 628<\/b>) est une\u00a0galaxie spirale<\/a>\u00a0qui est \u00e0 9,0\u00a0\u00b1\u00a01,1\u00a0Mpc<\/a><\/abbr>\u00a0(\u223c29,4\u00a0millions d’a.l.<\/a><\/abbr>) de la\u00a0Voie lact\u00e9e<\/a>. Elle est situ\u00e9e dans la\u00a0constellation des Poissons<\/a>. Elle a \u00e9t\u00e9 d\u00e9couverte par l’astronome fran\u00e7ais\u00a0Pierre M\u00e9chain<\/a>\u00a0en\u00a01780<\/a>, puis observ\u00e9e par\u00a0Charles Messier<\/a>\u00a0qui l’int\u00e9gra dans\u00a0son catalogue<\/a>\u00a0quelques semaines plus tard.<\/p>\n

M74 a \u00e9t\u00e9 utilis\u00e9 par\u00a0G\u00e9rard de Vaucouleurs<\/a>\u00a0comme une galaxie de\u00a0type morphologique<\/a>\u00a0SA(s)c dans son atlas des galaxies8<\/a><\/sup>,<\/sup>9<\/a><\/sup>.<\/p>\n

La\u00a0classe de luminosit\u00e9<\/a>\u00a0de M74 est III et elle pr\u00e9sente une large\u00a0raie HI<\/a>. Elle renferme \u00e9galement des\u00a0r\u00e9gions d’hydrog\u00e8ne ionis\u00e9<\/a>1<\/a><\/sup>.<\/p>\n

Avec une\u00a0brillance de surface<\/a>\u00a0\u00e9gale \u00e0\u00a014.40\u00a0mag<\/a>\/am<\/a>2<\/sup><\/span>, on peut qualifier M74 de\u00a0galaxie \u00e0 faible brillance de surface<\/a>\u00a0(LSB en anglais pour\u00a0low surface brightness<\/span><\/i>). Les galaxies LSB sont des galaxies diffuses (D) avec une brillance de surface inf\u00e9rieure de moins d’une magnitude \u00e0 celle du\u00a0ciel nocturne<\/a>\u00a0ambiant.<\/p>\n

De tr\u00e8s nombreuses mesures non bas\u00e9es sur le\u00a0d\u00e9calage vers le rouge<\/a>\u00a0(redshift<\/i>) donnent une distance de 7,380\u00a0\u00b1\u00a03,242\u00a0Mpc<\/a><\/abbr>\u00a0(\u223c24,1\u00a0millions d’a.l.<\/a><\/abbr>)\u00a010<\/a><\/sup>\u00a0, ce qui est \u00e0 l’int\u00e9rieur des distances calcul\u00e9es en employant la valeur du d\u00e9calage<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Donn\u00e9es d\u2019observation
\n(\u00c9poque<\/a>\u00a0J2000.0<\/a>)<\/small><\/th>\n<\/tr>\n
Constellation<\/a><\/th>\nPoissons<\/a><\/td>\n<\/tr>\n
Ascension droite<\/a>\u00a0(\u03b1)<\/th>\n01h<\/sup>\u00a036m<\/sup>\u00a041,7s<\/sup>1<\/a><\/sup><\/td>\n<\/tr>\n
D\u00e9clinaison<\/a>\u00a0(\u03b4)<\/th>\n15\u00b0\u00a047\u2032\u00a001\u2033<\/td>\n<\/tr>\n
Magnitude apparente<\/a>\u00a0(V)<\/small><\/th>\n9,4\u00a02<\/a><\/sup>
\n10,0 dans la\u00a0Bande B<\/a>\u00a02<\/a><\/sup><\/td>\n<\/tr>\n
Brillance de surface<\/a><\/th>\n14,40\u00a0mag<\/a>\/am<\/a>2<\/sup>3<\/a><\/sup><\/td>\n<\/tr>\n
Dimensions apparentes\u00a0(V)<\/small><\/th>\n10,5\u2032<\/a>\u00a0\u00d7 9,5\u2032<\/a>2<\/a><\/sup><\/td>\n<\/tr>\n
D\u00e9calage vers le rouge<\/a><\/th>\n+0,002192 \u00b1 0,0000031<\/a><\/sup><\/td>\n<\/tr>\n
Angle de position<\/th>\n25\u00b02<\/a><\/sup><\/td>\n<\/tr>\n
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Astrom\u00e9trie<\/th>\n<\/tr>\n
Vitesse radiale<\/a><\/th>\n657\u00a0\u00b1\u00a01\u00a0km\/s<\/a>\u00a04<\/a><\/sup><\/td>\n<\/tr>\n
Distance<\/th>\n9,0\u00a0\u00b1\u00a00,6\u00a0Mpc<\/a><\/abbr>\u00a0(\u223c29,4\u00a0millions d’a.l.<\/a><\/abbr>)\u00a05<\/a><\/sup><\/td>\n<\/tr>\n
Caract\u00e9ristiques physiques<\/th>\n<\/tr>\n
Type d’objet<\/th>\nGalaxie spirale<\/a><\/td>\n<\/tr>\n
Type de galaxie<\/a><\/th>\nSA(s)c1<\/a><\/sup>
\nSc2<\/a><\/sup>
\nSA(s)c?6<\/a><\/sup><\/td>\n<\/tr>\n
Dimensions<\/th>\nenviron\u00a026,4\u00a0kpc<\/a><\/abbr>\u00a0(\u223c86\u00a0100\u00a0a.l.<\/a><\/abbr>)x environ\u00a024\u00a0kpc<\/a><\/abbr>\u00a0(\u223c78\u00a0300\u00a0a.l.<\/a><\/abbr>)7<\/a><\/sup><\/td>\n<\/tr>\n
D\u00e9couverte<\/th>\n<\/tr>\n
D\u00e9couvreur(s)<\/th>\nPierre M\u00e9chain<\/a>\u00a06<\/a><\/sup><\/td>\n<\/tr>\n
Date<\/th>\n~fin septembre 1780\u00a06<\/a><\/sup><\/td>\n<\/tr>\n
D\u00e9signation(s)<\/th>\nNGC<\/a>\u00a0628
\nPGC<\/a>\u00a05974
\nUGC<\/a>\u00a01149
\nMCG<\/a>\u00a03-5-11
\nCGCG<\/a>\u00a0460.14
\nIRAS<\/a>\u00a001340+1532\u00a02<\/a><\/sup><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div><\/div><\/div>
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