Astr110 Photography Projects, Spring 2006

The Eyes, Kristen Irwin

The Eyes (NGC 4438 on the left and NGC 4435 on the right) are two galaxies situated close together in the sky. They are both right in the middle of the Virgo cluster. They are about 40 million light years away from the Earth. Both galaxies have an almost white center with parallel dust streams surrounding the center.

In the background of this picture, some of the many star-like looking objects are in fact many different galaxies. The most dominate galaxy is NGC 4438. It has faint arms that have been stretched out of their normal location by the gravitational forces of NGC 4435. These galaxies interact regularly due to their proximity.

The angular size between the centers of the two galaxies combined is approximately 5 minutes. Using the small angle formula to calculate the linear size of the object, we use the following formula: 14 million light years x (5 minutes/3,400) = 21,000 light years.

The angular size of the galaxy NGC 4438 is about 1 minute. Using the same formula, we can calculate the linear size of the galaxy. 14 million light years x (1 minute/3,400) = 4,000 light years.

References:
"NGC 4438: The Eyes." http://www.noao.edu/outreach/aop/observers/n4438.html

" NGC4438/35 - The Eyes Galaxies" http://www.schursastrophotography.com/ccdimagepages/ngc4438.html