A Trip South with the Lookout Observatory Staff
Dear Cosmic Fellow Travelers,
The whole Lookout Observatory staff (me) had the opportunity this month to travel to New Mexico to meet with a childhood friend, physicist Dr. Fritz Kleinhans. We were stationed 8 degrees of latitude south of Lookout Observatory, which gave us the opportunity to photograph cosmic objects not visible from much of the U.S. I’m sharing with you two galaxies, close neighbors to each other, which were low in the sky to the south, so still a challenge to photograph. Each of these galaxies appears in the sky to be about half the diameter of the full moon, but too faint to be seen with the naked eye.
First is the unique galaxy NGC 5128, also known as Centaurus A because it is the strongest (and first) source of radio wave emissions discovered in the constellation Centaurus. It’s peculiar appearance probably indicates that it is actually two galaxies that have collided and merged – a giant elliptical galaxy and a spiral galaxy. The center contains a supermassive black hole which shoots out an invisible jet of material perpendicular to the dark band, and this results in strong X-ray and radio emissions. It is a relatively close galaxy, about 13 million light years distant. Because it also has a high energy output in the visible wavelengths, it is the 5th brightest galaxy in the sky. In the area of the dark band very rapid star formation is taking place, making this galaxy one of the so-called “starburst galaxies.” Professional astronomers have studied this galaxy extensively because it is close and unique.
Second is the the galaxy M83, also known as the Southern Pinwheel Galaxy. It is a face-on barred spiral galaxy, large and bright (as galaxies go) because it is “only” about 15 million light years distant. The pinkish regions that follow the dark dust lanes are where new stars are being born, and the blue regions of the spiral arms are where older, hotter stars are shining in relatively dust-free regions. There is a French electronic music band, now based in Los Angeles, named “M83” after this galaxy. The leader is into astronomy and obviously likes this galaxy. You could listen to them while you look at this picture and feel really spacey!
By the way, these two galaxies, though several million light years apart, are probably linked by gravity. They are part of two groups of galaxies known together as the Centaurus A/ M83 Group, consisting of about four dozen galaxies. This group is a close neighbor of our Local Group, a grouping of about 50 galaxies gravitationally tied together. The two largest galaxies in our Local Group are the Milky Way Galaxy (where we live) and the Andromeda Galaxy (also known as M31). So the two galaxies photographed here, while not in our immediate neighborhood, are in the next neighborhood over, close enough to be friendly with.
Keep looking up,
Carter Mehl,
(Sometime) Resident Astronomer,
Lookout Observatory
Click on any image to get a closer look
