Seen face-on Messier 74 is a beautiful example of a “grand-design” spiral galaxy. This means that unlike other galaxies, Messier 74 has two distinct arms that spiral out from its center, known as a nucleus. This galaxy, like our own Milky Way, is composed of dust, gas, planets, and billions of stars. At the center of this galaxy are older stars, creating the brighter bulge in the middle. First discovered by Pierre Mechain in 1780 it is one of fourteen spiral nebulae discovered before 1850. Pierre Mechain showed his discovery to his friend, Messier, who included it in his catalog, giving it its name “Messier 74.”
The two symmetrical arms of Messier 74 are outlined in a glowing pink and blue. The pink are regions of ionized hydrogen, which are hydrogen atoms that have lost their electrons. The blue are young stars that have begun to form. Blue stars burn out quickly, and so do not last long enough to be seen outside of the spiral arms. Dust lanes also begin near the galaxy’s nucleus, and wrap around the spiral arms, giving it a hazy look. Located 32 million light-years away from earth and spanning 37,233 light-years across, Messier 74 is far larger than it looks.
Chandar, R, J. Miller. “Sprial Galaxy M74” <http://hubblesite.org/newscenter/archive/releases/2007/41/image/a/>.
“Galaxies.” National Geographic. <http://science.nationalgeographic.com/science/space/universe/galaxies-article/>.
“Messier 74.” <http://messier.seds.org/m/m074.html>.
|Right Ascension (J2000)||01:36:41|
|Filters used||B (Blue), C (Clear), R (Red), V (Green)|
|Exposure time per filter||B (120s x 4) V, R, C, (60s x 5)|
|Date observed||October 19, 2012|