Globular Cluster in Serpens

Uploaded 5/17/09

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One of the most spectacular globular (pronounced "globe-u-lar") clusters in the sky is M5 in the constellation of the Serpent. This object visually is only slightly less impressive than the brighter M13, andt has a few surprises. One is that two of its variables reach a brightness of at least 10th magnitude - a star designated as 42 and 84 in Coutts and Hogg's list. While most of the stars have magnitudes between 11 and 12, the integrated magnitude is 5.7 of all stars combined. The size of 22 arcmins puts it much larger than my 30 arcmin field. This objects color is a prime example of globular cluster stellar distributions. The main core is composed of blue super giants, surrounded by a periphery of orange super giant stars, both seen well in this image.
Instrument: 12.5" f/5 Home made Newtonian Mount: Astrophysics 1200 QMD CCD Camera: SBIG 10XME NABG with Enhanced Water Cooling Guider: Meade DSI w/Lumicon Newt Easy Guider Exposure: RGB = 20:20:20 AstroDon RGB Combine Ratio: 1: 1.05: 1.4 Location: Payson, Arizona, Elevation: 5150 ft. Sky: Seeing FWHM = 5 arcsec (Maxim DL - 10min subframe), Transparency 8/10 Outside Temperature: 45 F CCD Temperature: -30 C Image Processing Tools: Maxim DL: Calibration, deblooming (Starizona Debloomer), aligning, stacking PixInsight: Curves, Deconvolution, noise reduction Photoshop CS2: Curves, Color Correction, Gradient removal (Grad Xterminator), Cleanup HOME GALAXIES EMISSION NEBS REFLECTION NEBS COMETS GLOBULARS OPEN CLUST PLANETARIES LINKS