MESSIER 17

Open Cluster associated with Nebulosity in Sagittarius 

 (ra: 18:20.8 / dec - 16:11)

September 2010, Gouin - Buenos Aires, Argentina

DATA

TYPE: Open Cluster associated with Nebulosity

VISUAL MAGNITUDE: 6 (M17)

SIZE: 11 arc minutes (M17) The field of view is 80 x 60 arc minutes 

DISTANCE: 5.000 light years

OBJECT DESCRIPTION AND IMAGE SESSION

The Omega Nebula Messier 17 (M17, NGC 6618), also called the Swan Nebula, the Horseshoe Nebula, or (especially on the southern hemisphere) the Lobster Nebula, is a region of star formation and shines by excited emission, caused by the higher energy radiation of young stars. Unlike in many other emission nebulae, however, these stars are not obvious in optical images, but hidden in the nebula. Star formation is either still active in this nebula, or ceased very recently. A small cluster of about 35 bright but obscured stars seems to be imbedded in the nebulosity (*).

The color of the Omega Nebula is reddish, with some graduation to pink. This color comes from the hot hydrogen gas which is excited to shine by the hottest stars which have just formed within the nebula. (*)

There is a bluish tad over the Swan East area (to the left in the image) which I have seen in other few images like this great rendition of Chuck Vaughn

A late acquisition for the southern spring. The object was going west, so not much time available to round up all color channels. Nevertheless the fast Orion UK optics provided some lead to achieve a decent result.

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(*) SEDS

IMAGE INFORMATION

SCOPE: 6" Newtonian with Orion UK Optics at f5

SKY CONDITIONS: Good transparency but some street lights gradients. Regular seeing.

CAMERA: QSI 583 WS -15Cº

FILTERS: Astronomik Type 2, Ha 6nm

EXPOSURES: LHaRGB (30,20,20,20,20)  L bin 1x1, HaRGB bin 2x2

GUIDING: Synta 70/400 refractor. Starlight Xpress Lodestar Camera. AA 3.71 Control Camera Plug-in

PROCESSING: No darks, nor flats, nor offsets. Images Plus (Sigma Median Combination) CCD Sharp Richardson Lucy Deconvolution Photoshop CS