Center of the Heart Nebula (Melotte 15 in IC 1805)

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About this Image

The bright star cluster, known as an "open cluster" centered in this image is known as Melotte 15 after its discoverer, Philibert Jacques Melotte (1880-1961). Melotte 15 is embedded within and illuminates the central portion of the much larger glowing nebula identified as IC 1805.

The interesting structure in the center of the image is a giant area of hydrogen gas that is caused to glow by the intense ultraviolet radiation from the massive stars of the Melotte 15 star cluster.
Dust and gas clouds are eroded by the pressure of the intense radiation.
The Melotte 15 star cluster is estimated to be 7,500 light years away from Earth.
North is to the upper left corner.

Technical Details


16" cassegrain in secondary focus at f/10

Mount MK-100 GEM
Camera SBIG STL-11000M at -30C, internal filter wheel, AO-L
Filters Astronomik HaRGB
Date Dec 27 - Jan 15, 2007.
Location Wildon/Austria
Sky Conditions mag 5.5 sky, raw FWHM 1.8 - 2.4", temperature 0 C,
Exposure Ha:R:G:B= 180:60:60:60 min
(60 min subs for H-alpha, 20-minute sub-exposures for RGB) all 1x1.
Processing Image aquisition in Maxim DL 4.56; Calibration, stacking and deconvolution in CCDStack; Final processing in Photoshop CS2