w20160801 M13 8acfsct A7R iso3200 4x120s 1800px

Messier 13 (M13), also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules or the Hercules Globular Cluster, is a globular cluster of about 300,000 stars in the constellation of Hercules.


M13 is about 145 light-years in diameter, and it is composed of several hundred thousand stars, the brightest of which is a red giant, the variable star V11, with an apparent visual magnitude of 11.95. M13 is 25,100 light-years away from Earth.

ObjectM13 or NGC 6205 - Hercules Globular Cluster
Constellation: Hercules
Position: RA 16h 41m 41.24 DEC +36° 27′ 35.5″
Apparent Size: 145Lj = 20 arcmin
Apparent Magnitude: +5.8
Distance (average) 22.2 kly
Photo Datas 
Date 01.08.2016, 20:00 UTC
Location Knottenried/Oberallgäu, 1002m ASL
GPS: 47°36’13“ N, 10°11’24“ E
Sky darkness SQM-L Object 20.5mag/sqrsec, Zenit 20.5mag/sqrsec
Ground Temp./Air Pressure 15°C /
Thermal sky temp./weather         /high altitude haze
Telescope Meade  8" SC ACF 2032mm f/10.0, no flattener
Camera Sony A7R unmod @ T sensor=20°C
Expose frames ISO 3200, RAW 4x120s, 2 darks, 2 flats
Total expose
8 min.
Filter no
Mount FS2
Guiding Cam no
Software DSS 3.3.4, Photoshop CC
Remarks My first astro photo (quick shot) without proper features
(not fully dark during astronomical twilight - poor seeing - high altitude haze).

 C 2016 Peter Cerveny