IC 1805, the Heart Nebula


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IC 1805 is the so-called Heart Nebula. This 3 panel mosaic encompasses an East-West view crossing the Heart from its top (East) to its bottom. This region is a very active star forming nebulosity. Proof of that is that it is plagued with Young Stellar Objects (YSOs, hundreds of them are visible here) and really most of the bright spots visible in the image are YSOs. Very conspicuous in the middle of the image is Melotte 15, a young open cluster that is ionizing and modeling its surroundings.


This image has been processed by mapping the colors to the Hubble Color Palette (SII to Red, Halpha to Green and OIII to Blue). Although I nearly always prefer to map the colors to the natural ones (even in images taken through narrowband filters), in this case, the Hubble Color Palette helps to better differentiate between areas with different compositions and shows a great deal of different colors and nuances, not visible otherwise in the natural color mapping (see this image below). Even a remarkably red, very intense in sulphur emission, “fat integral sign” nebulosity appears very well differentiated on the lower border of the right third of the image.



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The total exposure time for this image has been 99 hours 10 minutes.

Additional Information


Name(s): IC 1805, Sh2-190, Melotte 15, The Heart Nebula

Type: Emission Nebula

RA:  02h 33m 22s

Dec: +61º 26’ 36”

Constellation: Cassiopeia

Size (arcmin): 150×150 arcmin

Magnitude: +18.3

Distance: 7,500 ly


Date: 2019-10-13 to 2019-12-22

Location:New Mexico Skies, Mayhill, NM, USA

Size (arcmin): 82×30 arcmin

Telescope: 24” f/6.5 Reflector

Camera: FLI PL16803 (4096x4096pix)

Guiding: Astrodon MonsterMOAG off-axis guider

Total exposure: 99h 10m (Ha: 43h 20m; OIII: 28h; SII: 23h 20m; RGB (stars): 4h 30m)

Processing: CCDStack, Photoshop CC 2020







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