Hubble Space Telescope picture of the spiral galaxy IC 342, also understood as Caldwell 5, which has the nickname, Hidden Galaxy. Credit: NASA, ESA, P. Sell (University of Florida), and P. Kaaret (University of Iowa); Image processing: G. Kober (NASA Goddard/Catholic University of America
Spiral galaxy IC 342, also understood as Caldwell 5, lies approximately 11 million light-years from Earth. Hubble caught this gleaming, face-on view of the center of the galaxy, which shows linked tendrils of dust in amazing arms that twist around a fantastic core of hot gas and stars.
This core is a specific kind of area called an H II nucleus– a location of atomic hydrogen that has actually become ionized. Such regions are energetic birthplaces of stars where countless stars can form over a number of million years. Each young, extremely hot, blue star emits ultraviolet light, more ionizing the surrounding hydrogen.
Despite its reasonably brilliant 8.4 magnitude, this galaxy does not stand apart in the sky. It appears near the equator of the Milky Ways pearly disk, which is crowded with thick cosmic gas, dark dust, and glowing stars that all obscure our view. This has earned Caldwell 5 the label 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 fairly close galaxy, it is roughly 50,000 light-years across and billions of years of ages.
By NASAs Goddard Space Flight
May 16, 2022