IC342 – the hidden galaxy in HaLRGB – comparison of original and dereddened image

About the Object

IC342 in the constellation Camelopardalis , also known as "the hidden galaxy", is a quite interesting object. It IC342 is a barred spiral galaxy with an active galactic nucleus. Being the brightest object in the Maffei group, i.e. the galaxy group next to our home, the Local Group, it actually is by apparent size the third largest galaxy after M31 and M33 on the sky (i.e. larger than M81 and M101). As such it should be visible by naked eye if it would not be located in the Galactic plane and thus hiding behind the dust curtain of our Milky Way. The Galactic dust not only makes IC342 comparably dim, it also takes out quite a bit of its color and makes it overall greyish-yellow-brown.  The strong extinction also makes processing IC342 data quite difficult.

UV observation with GALEX show extended star formation in IC342, as also shown by the substantial H_alpha structures in this HaLRGB image.

Observation Notes

How would IC342 look like if it would be located well outside the Galactic plane? I estimated the reddening in the RGB colors by using a Schlegel&Finkbeiner dust map, brightened the G and B bands accordingly, and then followed the further process as similar as possible to the original processing.

Data were taken on Nov  23, 26, 30, and Dec 1

Technical Details

View the full-resolution image together with complete acquisition and processing details on AstroBin.