BAADE'S WINDOW NGC 6522 & 6528

Globular Clusters is stellar star field

 (ra: 18:20.8 / dec - 16:11)

September 2010, Home Backyard in Martínez - Buenos Aires, Argentina

DATA

TYPE: Globular Clusters in stellar field

APPARENT MAGNITUDE: 8.6 (NGC 6522); 9.5 (NGC 6528)

SIZE: 5.6 arc minutes for NGC 6522; 3.7 arc minutss for NGC 6528

DISTANCE: 25.800 / 25.400 light years

OBJECT DESCRIPTION AND IMAGE SESSION

Located in Sagittarius, the Baade's Window is an unusual transparent region 4º south from the galactic center with low concentration of interstellar dust. Through this area is possible to see the stars of the central bulge. The window is about 1 degree around the globular cluster NGC 6522. German Astronomer Walter Baade was able to determine by lat 1940's the first reliable distance to the centre of the Galaxy. Modern measurements place it at about 25,000 light years away, slightly greater than Baade's result, which was published in 1951. (*)

The stars in the image are probably older than our own Galaxy. NGC 6522 is the one on top and they are separated by 16 arc minutes. The bright star at the left of NGC 6522 is SAO 186186 and shines at magnitude 7.40. It was a regular night with half Moon, good for testing equipment and for bright targets as this one.
 

.(*) Australian Astronomical Observatory

IMAGE INFORMATION

SCOPE: 8" SCT @ f6.3

SKY CONDITIONS: Bad transparency; regular seeing.

CAMERA: QSI 583 WS -15Cº

FILTERS: Astronomik Type 2,

EXPOSURES: LRGB (15,15,15,15)  LRGB bin 2x2

GUIDING: WO Zenithstar 66. Starlight Xpress Lodestar Camera. AA 3.71 Control Camera Plug-in

PROCESSING: No darks, nor flats, nor offsets. Images Plus (Sigma Median Combination) CCD Sharp Richardson Lucy Deconvolution Photoshop CS