IC 4628 (aka Gum 56)

Bright Emission and Reflection Nebula in Scorpius

(ra: 16,57.0 / dec -40:20)

June 2011,  Mercedes - Buenos Aires, Argentina

DATA

TYPE: Emission Complex    

Apparent Magnitude: n/a

Apparent Diameter: 90  arcs minutes

DISTANCE: 6000 light years (estimate)

IMAGE INFORMATION

SCOPE: Orion Optics UK 150/750 f5 Ultra Grade Mirror with Baader MPCC

CAMERA: QSI 583 WS

MOUNT: NEQ6

GUIDING: Synta 70/400 refractor with Starlight Xpress LodeStar AstroArt 3.0 - Control Interface 3.72 plug in

FILTERS: Baader 2" LRGB downsized to 31 mm, Astronomik Ha 6 nm 

SKY CONDITIONS: transparency and seeing good

EXPOSURES: LHaRGB (90,60,30,30,30) HaRGB bin 2x2

PROCESSING: Calibration in Images Plus Sigma Media (no darks, flats, bias applied), CCD Sharp, NASA Photoshop Fits Liberator, Photoshop CS2

OBJECT DESCRIPTION AND IMAGE SESSION

An impressive arc shaped rim of HII structure is located in the tail of the Scorpius constellation and known as the Prawn Nebula. The center portion of the nebula is very bright and it seems there is a faint reflection component embedding it. Bright stars are part of Open Cluster named Trumpler 24 which shines at magnitude 8.6 and spans over 60 arc minutes representing approximately 250 light years across.