HOME

BACK

GUM 46 - AKA RCW 71

HII PATCH IN CRUX (THE SOUTHERN CROSS) 

(Image centered at ra: 12h:50m:23s / dec -61º 24')

 

 

May 2026, Home Backyard in Martinez, Buenos Aires, Argentina

 


 

DATA

TYPE: Emission Nebula

Visual Brightness: N/A

APPARENT DIAMETER: 3 arc minutes

DISTANCE: 6800 light years

 

IMAGE INFORMATION

SCOPE: 6" ORION OPTICS UK (Ultra Grade Optics) w/Sky Watcher Coma Corrector (0.9x) working at at f4.5

CAMERA: QHY 183 MONO

MOUNT: VIXEN GP DX MOUNT, OAG with QHY 5II Mono

FILTERS:  OPTOLONG LRGB Set Antlia 3nm HA

SKY CONDITIONS: Urban Skies. Bortle 9

EXPOSURES: LHARGB (45,120,45,45,45) - all channels bin 1x1

 

OBJECT DESCRIPTION AND IMAGE SESSION

RCW 71  or Gum 46 is a rather small HII patch in the sky located at the border of the Coalsack Dark Nebula. Since the Coalsack Dark Nebula is much closer, roughly at 650 light years, its interstellar dust and gas block the distance light an produce a reddened effect. The glowing core of RCW71 spans over 4 light years, and its is powered by the intense ultraviolet radiation of a hot and massive 09.5V star HD311999. The ionized star belongs to infrared open cluster [DBS2003] 80. Infrared observations have revealed that the nebula is actually surrounded by a massive, faint emission ring extending up to 6 arc minutes across.