[an error occurred while processing this directive]
Calvin Observatory
Weather Forecast
Cool Images
Observing Request
External Links
Related Links
Wildrik Botjes Planetarium
Physics & Astronomy Department

Astr110 Photography Projects, Fall 2007

Previous imageUp to Astr110 IndexNext image

NGC 2403 Spiral Galaxy, Derek Elenbaas

Spiral Galaxy NGC2403

The spiral galaxy 2403 is an outlying member of the M81 group of galaxies. It is approximately 12 million light years away and can be seen from earth near the giraffe constellation, Camelopardalis. A spiral galaxy is a flattened, rotating galaxy with pinwheel-like spiral arms winding outward from the galaxy's nuclear bulge. It is a network of millions of stars in combining together to illuminate a vast area. The Milky Way, the galaxy earth is a part of, is a well-known example of a spiral galaxy. NGC 2403 was originally discovered in 1788 by William Hershel. In 2004, NGC 2403 was home to one of the brightest supernovas of modern times.

The image seen of this spiral galaxy reveals many interesting facts regarding it. The blue color of the stars that can be seen just above the nuclear bulge tells us that these stars are particularly hot. Because there are no obviously red stars, we can assume that there are few prominent cold stars in this galaxy. The yellow color of the nuclear bulge and the area around it tells us that the general temperature of the stars of this galaxy are average.The size of the stars also tell us about the galaxy. The smaller stars are relatively young and the larger stars are older in age. This galaxy is an average age because there are both large and small stars evident in the image. The spiral nature of this galaxy can be seen by the very faint spiral arms surrounding the nuclear bulge. These faint arms appear almost as a dusty cloud around the nuclear bulge, but with a close look, one can see the spiraling shape of this dust cloud and its appearance to be pin wheeling. The linear size of the galaxy is approximately 5.9 degrees in width.


Fraknoi, Andrew , David Morrison, and Sidney Wolff. Voyages Through the Universe. 3rd ed. Canada: Thomson Learning, 2004.

Frommert, Hartmut and Kronburg, Christine. "NGC 2403." Students for the Exploration and Development of Space. <http://seds.lpl.arizona.edu/messier/xtra/ngc/n2403.html>.

Nemiroff, Robert and Bonnell, Jerry. "Astronomy Picture of the Day." <http://apod.nasa.gov/apod/ap060705.html>

Right Ascension (J2000) 07:36:54
Declination (J2000) 65:36:00
Filters used blue(B), green(V), red(R), and clear(C)
Exposure time per filter 5x60 seconds in C, 300 seconds in BVR
Date observed

October 19, 2007