NGC 6204 & HOGG 22 (*) - OPEN CLUSTERS

ARA

 ((Image Centred at ra: 16.47,11/ dec -47:4)

August 2009, Home Backyard in Martínez - Buenos Aires, Argentina

DATA

TYPE: Open Cluster Pair

Apparent Magnitude: 8.2 (NGC 6204); 6.7 (Hogg 22)

Apparent Diameter: 6 arc minutes (NGC 6204); 1,5 arc minutes (Hogg 22)

DISTANCE: not found

IMAGE INFORMATION

SCOPE: Celestron SCT 8" working at f5

CAMERA: SXVF H9

GUIDING: William Optics ZenithStar 66

IMAGE ACQUISITION: AstroArt 3.0 - Control Interface 3.72 plug in

FILTERS: Astronomik Type II - Atik Filter Wheel

SKY CONDITIONS: urban skies - transparency and seeing regular

EXPOSURES: LRGB (20,20,20,20)

PROCESSING: Images Plus, CCD Sharp, Photoshop CS2

OBJECT DESCRIPTION AND IMAGE SESSION

I was searching for two Open Clusters that might be gathered in the SCT 8" field of view. The candidate was this nice pair in the Southern Constellation of Ara. Unfortunately no much pictures of this object were found. Both cluster are in our Galactic plane so they share the background with old brownish stars. The pair is located approximately 4 degrees south from Zeta Scorpii. 

NGC 6204 contains 45 stars in a field of 5 degrees with stars magnitudes ranged from 9 to 12. Hogg 22 is even smaller with only 1.5 arc minutes but higher in brightness. The cluster is mainly formed by four stars in "diagonal shape" which are pointing at NGC 6204. 

(*) Helen Sawyer Hogg (1905 - 1993) was a Canadian prolific astronomer who studied and researched open clusters.