IC 342

Click on the image to display it full screen

Observation place
New Mexico


TelescopePlanewave 431mm - 17 ″, 1mm FL, f / 940 with focal reducer
MountPlanewave Ascension 200HR (FLI)
Imaging cameraMicroline PL6303E (FLI) - regulated at -35o Celsius
Image typeLHa (RHaVsB) (Vs for synghetic green)
LHa: Luminance using the clear filter + the Ha filter
RHa: Red layer using red filter + Ha filter
This composition was used to bring out the nebulae in the galaxy
ExhibitionLuminance (10 x 10 'bin 1 × 1), Ha (4 x 10' bin 1 × 1) R and B (4 x 3 'bin 2 × 2 each)
PretreatmentMaxim DL
TreatmentPhotoshop and PixInsight
Specific treatmentCreate a synthetic green image

Object description

Object typeSpiral galaxy front view "The hidden galaxy"
Visual magnitude 8,4
Surface gloss14,9
Distance10 million light years
Diameter35000 light years
Dimension seen from Earth21,4 x 20,9 arc minutes
IC 342 (also known as Caldwell 5) is an intermediate spiral galaxy in the constellation Giraffe. It is located just 10 degrees from the Galactic Equator. It is then heavily obscured by Milky Way dust, making it difficult to observe. This has earned it the nickname 'The Hidden Galaxy'. It contains 100 billion stars! It is only 10 million light years from Earth. It is therefore part of the local group of galaxies.  

Visually, the galaxy is observable only in a site of low light pollution. With a telescope with a diameter of 100 mm (4 inches), the core is visible and is surrounded by a light haze of light that extends for about half a dozen arc minutes. The galaxy is most easily seen in a 200mm (8 inch) diameter telescope where it appears in a moderately bright and fuzzy circular shape. Only the very large amateur instruments of 350 mm (14 inches) or more reveal the spiral arms of the galaxy.  

In my image, which was taken in a sky without light pollution (in New Mexico), we can appreciate the very great beauty of the galaxy. In order to bring out the star formation regions (places where there are emission nebulae), I integrated a Hydrogen-Alpha filter in my series of images, which made it possible to bring out these regions (see in pink in my picture). We can also observe the very weak signal of the arms of the galaxy which appear in hazy form since they are drowned in the dust of the arms of our galaxy, the Milky Way! We can also observe another galaxy, at the bottom left, listing UGC 2826. It has a visual magnitude of more than 15 and its apparent dimension (seen from Earth) is 1,2 x 0,9 arc minutes.
Richard Beauregard
Sky Astro - CCD
My impression "We cannot be alone in this gigantic universe"