The Grand Spiral Galaxy from Hubble
M74 (NGC628) is a grand spiral galaxy located approximately 32 million light-years away in the constellation Pisces. The image is 31,000 light-years wide. Credit: NASA/ESA Hubble Space Telescope.
This nearly face-on galaxy M74 is a stunning example of a “grand-design” spiral galaxy. Its well-defined spiral arms are dotted with clusters of young blue star and glowing pink regions of ionized hydrogen (hydrogen atoms that have lost their electrons), with winding dust lanes that begin very near the galaxy’s nucleus and tracing all the way along the spiral arms. This is just breathtaking!
M74 is slightly smaller than our Milky Way galaxy, containing about 100 billion stars. It is the dominant member of a small group of about half a dozen galaxies, the M74 galaxy group.
Usually a stunning image like this is not taken one shot. It is composite image created using a few different kinds of filters. In this case of M74, the filters used to create the color image isolate light from blue, visible, and infrared portions of the spectrum, as well as emission from ionized hydrogen.
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