Pierre Méchain discovered the M74 galaxy at the end of September 1780. This spiral galaxy is located in the constellation Pisces, 32 million light-years away. After observing the galaxy, Méchain reported his discovery to Charles Messier, who found its position and included it in his catalog. The galaxy is seen from earth face-on and has been classified as a SA(s)c galaxy. This classification means that the galaxy is spiral and does not have a bar or a ring. The galaxy is composed of about 100 billion stars. In the central bulge, the stars are very old. But in the surrounding arms, the stars are forming or newly formed.
The older stars in its central bulge appear yellow in the color photo. In the blue arms are areas of stars that are very young or just forming. The arms also house HII regions, which appear red as the hydrogen gas atoms emit energy. The dark portions of the galaxy are the collections of dust. M74 has been found to be about the same size as our own galaxy, the Milky Way. As calculated from the image above, M74 is about 37,000 light years in diameter.
Frommert, Harmut, and Christine Kronberg. Messier 74. Students for the Exploration and Development of Space. 2 Sept. 2007. Web. 4 Dec. 2010. <http://www.seds.org/messier/m/m074.html>.
Nemiroff, R., & Bonnell, J. “M74: The Perfect Spiral.” NASA Astronomy Picture of the Day, 1 Dec. 2007. Web. 6 Dec. 2010. http://antwrp.gsfc.nasa.gov/apod/ap071201.html
|Right Ascension (J2000)||01:36.7|
|Filters used||blue(B), green(V), red(R), and clear(C)|
|Exposure time per filter||60 seconds in B, 300 seconds in CVR|
October 25, 2010