IC 342

IC 342, Hidden Galaxy.jpg
Autor/Urheber: Judy Schmidt from USA, Lizenz: CC BY 2.0

Famously overlooked grand design spiral galaxy IC 342 as seen last year (2019 Oct) by Hubble. It is situated rather close to the plane of our own galaxy, making it difficult to discern through all the dust and stars between us and it. It's similar in size to the Triangulum Galaxy, but dimmed so much by dust that it wasn't discovered until a couple hundred years later. Joint observations with the Chandra X-ray Observatory are ongoing as astronomers survey for various x-ray emitting stellar sources within the galaxy.

Data from the following proposal were used to create this image: The Giant Hiding in Our Backyard: The Nearby Spiral Starburst Galaxy IC 342

This was my first attempt at assembling a mosaic using Astrodrizzle. I don't yet know how to align different filter sets to one another, but the mosaic assembly was much simplified by letting the software take care of it. It's misaligned by maybe half a pixel in some places, and less than that overall. Not perfect, but I will continue to learn.

I increased the saturation substantially for the final image. Cyans were shifted to slightly bluer hues using Camera Raw. Small triangles were filled with cloned data in all four corners in an attempt to eke just a little more overall data into the frame.

Red: ACS/WFC F606W Green: Pseudo Blue: ACS/WFC F435W

North is up.

IC 342 by Spitzer (3.6 to 24 µm).jpg
Looking like a spiders web swirled into a spiral, the galaxy IC 342 presents its delicate pattern of dust in this image from NASAs Spitzer Space Telescope. Seen in infrared light, the faint starlight gives way to the glowing bright patterns of dust found throughout the galaxys disk.

At a distance of about 10 million light-years, IC 342 is relatively close by galaxy standards, however our vantage point places it directly behind the disk of our own Milky Way. The intervening dust makes it difficult to see in visible light, but infrared light penetrates this veil easily. It belongs to the same group as its even more obscured galaxy neighbor, Maffei 2.

IC 342 is nearly face-on to our view giving a clear, top-down view of the structure of its disk. It has a low surface brightness compared to other spirals, indicating a lower density of stars (seen here in blue). Its dust structures show up much more vividly (yellow-green).

New stars are forming in the disk at a healthy clip. Glowing like gems trapped in the web, regions of heavy star formation appear as yellow-red dots due to the glow of warm dust. The very center glows especially brightly in the infrared, highlighting an enormous burst of star formation occurring in this tiny region. To either side of the center, a small bar of dust and gas is helping to fuel this central star formation.

Data from Spitzers infrared array camera (IRAC) are shown in blue (3.6 and 4.5 microns) and green (5.8 and 8.0 microns) while the multiband imaging photometer (MIPS) observation is red (24 microns).

Band		Wavelength	Telescope
Infrared	3.6 µm		Spitzer IRAC
Infrared	4.5 µm		Spitzer IRAC
Infrared	5.8 µm		Spitzer IRAC
Infrared	8.0 µm		Spitzer IRAC
Infrared	24.0 µm		Spitzer MIPS

Position (undefined)
RA = 3h 46m 15.0s
Dec = 68° 8' 13.7"

Field of View
33.3 x 28.4 arcminutes

Orientation
North is 139.1° left of vertical

IC 342 by Giuseppe Donatiello.jpg
Autor/Urheber: Giuseppe Donatiello, Lizenz: CC0
IC 342 is a front spiral galaxy SAB(rs)cd [IPAC database] in Camelopardalis and is one of the brightest two galaxies in the IC 342/Maffei Group at a distance 10.7 ± 0.9 Mly. The galaxy was discovered by William Frederick Denning in 1895. (J2000) RA: 03h 46m 48.5s Dec: +68° 05′ 46″

Hubble's Hidden Galaxy.jpg
(c) ESA/Hubble, CC BY 4.0
Caldwell 5, also known as IC 342, is a spiral galaxy located approximately 11 million light-years from Earth. This sparkling, face-on view of the center of the galaxy displays intertwined tendrils of glowing, rosy dust in spectacular arms that wrap around a brilliant blue core of hot gas and stars. This core is a specific type of region called an H II nucleus — an area of atomic hydrogen that has become ionized. Such regions are energetic birthplaces of stars where thousands of stars can form over a couple million years. Each young, extremely hot, blue star emits ultraviolet light, further ionizing the surrounding hydrogen.

Despite its 8.4 magnitude, Caldwell 5 is very difficult to find in the sky. The galaxy appears near the equator of the Milky Way’s pearly disk, which is crowded with thick cosmic gas, dark dust and glowing stars that all obscure our view. Therefore, in order to distinguish the intricacies of Caldwell 5 through a telescope, astronomers must peer through light-years of space chock-full of visual hindrances. This has earned Caldwell 5 the nickname of the Hidden Galaxy.

Were it not obscured by so much interstellar matter, the Hidden Galaxy would be one of the brightest galaxies in our sky. A relatively close galaxy, it is roughly 50,000 light-years across and billions of years old. Its face-on alignment makes it a prime target for possible supernova sightings, but so far, scientists have seen none.

Caldwell 5 was discovered in the early 1890s by William Frederick Denning, a British amateur astronomer who had practically no formal scientific training yet still managed to achieve a great amount of success in astronomy (discovering several comets, publishing more than a thousand scholarly articles, and winning the Gold Medal of the Royal Astronomical Society). The best time of year to look for Caldwell 5, which is located in the constellation Camelopardalis, is during late autumn and early winter in the Northern Hemisphere. In the Southern Hemisphere, only those located close to the equator will have a chance to spot it low in the northern sky during late spring or early summer. True to its name, the Hidden Galaxy can be difficult to find, especially if your sky is light polluted or even slightly cloudy or hazy. Wait for the clearest of nights and travel away from city lights to search for it with a telescope.

This image of the center of Caldwell 5 is a combination of visible and ultraviolet observations captured by Hubble’s Wide Field Camera 3. Astronomers used Hubble’s observations to learn more about the stars clustered at the center of the galaxy.

Caldwell Catalogue.jpg
Autor/Urheber: Roberto Mura, Lizenz: CC BY-SA 3.0
Caldwell Catalogue objects.