Comparison of Omega Centauri and M13

Click on the image for a higher res version - MOUSE OVER for a comparison with a simpler but identical processing

We, observers of the Northern hemisphere, cannot even imagine a globular cluster better than M13 in Hercules. But we're missing that in the deep South some gems are hidden, such a the master of all clusters: Omega Centauri. So bright that, the name reveals, it was mistaken for a star!
This is a not fair comparison because each image was processed independently to extract as much as possible. I've made also a comparison with a simpler but identical processing, and M13 is even more ugly: see mouse over.

For a comparison of the 6 best globular cluster of the whole sky, look at "The best globular clusters"; or for only Omega Cen look at "Omega Centauri globular cluster".
 
Technical Data
Optics Takahashi FS152 apo refractor
Focal Lenght 1216 mm (direct focus, no flattener)
Focal Ratio f/8
Exposure Time For each image, respectively: 1h30min, 1h30min (single exp of 10 min)
CCD Canon EOS 5D with Baader filter
Sensitivity 800 ISO
Location Omega Cen: Tivoli Farm (Namibia) at 1350 m height; M13: Bogli (PC, Italian Apenines) at 1350 m
Date
Omega Cen: 28 August 2011; M13: 2010
Mount Omega Cen: Fornax 51; M13: 10Micron GM2000
Tracking SXV-H5 on a Vixen 80/640 apo refractor
Temperature and humidity T= 15 °C, RH= 27 %
Sky brightness at zenith (with SQM-L) 21.6 mag/arcsec^2
Notes This image is a collaborative effort of the Namibia 2011 expedition. Processing: Lorenzo Comolli. Images by: Lorenzo Comolli, Luigi Fontana, Giosuè Ghioldi, Emmanuele Sordini.
M13 was imaged by Giosuè Ghioldi with the same telescope and camera from the Northern hemisphere.


HTML Editing and Publishing by Lorenzo Comolli. Email me at comolli@libero.it.
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