NGC 3198 - AKA BLUE PLANETARY

 PLANETARY NEBULA IN CENTAURUS  

(Image centered at: ra 15 h:51 m / dec - 57º 18')

April 2022, Sarandi, Gualeguayachu, Entre Rios, Argentina

DATA

TYPE: Planetary Nebula

APPARENT DIAMETER: 23 arc seconds 

VISUAL BRIGHTNESS: 8,1

DISTANCE: 3000 light years

IMAGE INFORMATION1

INSTRUMENT: 8" ORION OPTICS UK (Ultra Grade Optics) w/Televue Paracorr working at at f5,75

CAMERA: QSI 583 WS

MOUNT: SKY WATCHER NEQ6, OAG with Starligh Xpress Lodestar

FILTERS: Baader LRGB Set

SKY CONDITIONS: rural skies - humid night

EXPOSURES: RGB (20,20,20)

OBJECT DESCRIPTION AND IMAGE SESSION

NGC 3918 is a bright planetary nebula nicknamed as "Blue Blanetary". Very small in its relative diameter, it can be observed with small telescopes. At 50 x appears as a pale oval disc with a diameter of 10 arcs seconds. Long exposure photography shows a bit more of the outer shells. It real diameter is calculated in 0,3 light years. It was discovered by Sir John Herschel in March 1834 from Cape Town, South Africa.

Some outer layers were captured in RGB which are expanding from stellar winds generated by the central star at 24 kilometres per second.