Melotte 15

Melotte 15 - Open Star Cluser in IC 1805

Melotte 15 is a very young star cluser in the IC 1805 nebula, also known as the Heart Nebula. It consists of massive OB stars with a mean age of only 1.5 million years. Melotte 15 is one of the core clusters of the Cas OB6 stellar association.

Image Type:	Narrowband	Constellation:	Cassiopeia
Telescope:	10" Aries f/15 Maksutov-Cassegrain on Astro-Physics 900GTO German Equatorial	Object:	Open Star Cluster, type III 3 p n
Focal Length:	2692mm	Distance:	7,500 light years
Resolution:	0.52"/pixel at full size	Dimensions:	21'
Accessories:	Moravian G1-0300 as Off-Axis Guider, 0.67X Astro-Physics CCD Telecompressor	Magnitude:	~6.5 (V)
CCD:	QSI 532wsg, running at -20 deg. C
Exposures:	3nm Narrowband [H II]: 6.75 hours [O III]: 6 hours, total: 12.75 hours	Aries MCT in Malvazinky Observatory
Filter(s):	Astrodon Narrowband and Tru-Balance E-Series
Exposure Date:	September 24 to October 2, 2011
Location:	Malvazinky Observatory in Prague, Czech Republic
Seeing, FWHM:	Not Measured
Processing Software:	MaximDL, PixInsight, Photoshop
Image Acquisition Software:	MaximDL, TheSky6, CCDAutoPilot, FocusMax, PinPoint
Remarks:	Czech Astrophotography of the month (January, 2012) 8Mag Amateur Astrophotographer of the Month Award (January, 2012) Publication: MF Dnes Newspaper (February 10, 2012) Processing method: LRGB Combination (R=[H II], G=[O III], B=[O III]) Histogram Transformation Split to RGB ATrousWaveletTransform on G and B channels (K-Sigma Noise Thresholding) to denoise Generate Star Mask ATrousWaveletTransform to bring details out (with noise suppression) Resample to 1600px horizontal (resample mask too) ATrousWaveletTransform to bring details out (with noise suppression) Export to PNG Photoshop: Create Grayscale Layer via Desaturate Overlay Grayscale as Luminosity over RGB Layer Select stars, expand 5 pixels, feather 5 pixels, invert Shadows/Highlights: Shadows 1%, Width 56%, Radius 300px, Highlights 0%, Midtone Contrast +30 Flatten Levels (Subjective) Noise Filter - selective low luminosity (low SNR) parts Unsharp Mask