NGC 6188 & NGC 6193

STAR FORMING REGION IN ARA

 (ra 16:41.3/ dec -48:46)

May 2013 - Camping La Porteña - San Antonio de Areco, Buenos Aires, Argentina

DATA

TYPE:  Open Cluster and Nebulosity Complex in ARA

Apparent magnitude: NGC 6193 5.2

Apparent diameter: 20 arc minutes

Distance: 3765 light years for NGC 6193

IMAGE INFORMATION

SCOPE: Carbon Fiber Ritchey Chrétien 8" f8 

CAMERA: QSI 583 WS

FILTERS: Baader LRGB, 2" IDAS LPS for all channels

SKY CONDITIONS: rural skies 75% Moon

EXPOSURES: LHaRGB (60,30,30,30,30)

OBJECT DESCRIPTION AND IMAGE SESSION

NGC 6193 is a remarkable young stellar cluster which represents the core of the Ara OB1 stellar association. The stars of the vast Ara OB1 association span a full square degree of southern sky. The cluster NGC 6193 is imbedded in an area cloaked by thick gas clouds and obscuring lanes of dust. The hottest stars of the cluster, two closely spaced O-type giants HD 150135 and HD 150136, (the bright stars in the image) are the illumination source of the emission nebula NGC 6188. HD 150136 is a remarkable binary system comprised of a massive O3 type and O6V type stars which are nearly in contact with each other. Colliding stellar winds from the pair may be responsible for the prodigious x-ray emission emitted from this bright stellar system.

NGC 6193 and its emission counterpart NGC 6188 are seen in projection along the edge of a molecular cloud and immense expanding bubble of neutral hydrogen gas spanning some 300 light years. Ultraviolet radiation from the O-type giants of NGC 6193 is presently eroding the eastern edge of the parent molecular cloud and may be triggering and sustaining further star formation in other regions within it. (*)

(*) Robert Gendler essay on NGC 6188 and NGC 6193