Blog

Dazzling Darkness

June 23, 2017

“The strongest affection and utmost zeal should, I think, promote the studies concerned with the most beautiful objects. This is the discipline that deals with the universe's divine revolutions, the stars' motions, sizes, distances, risings and settings...for what is more beautiful than heaven?” - Copernicus

“The cosmos is all that is or ever was or ever will be. Our feeblest contemplation of the Cosmos stir us – there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, or falling from a height. We know we are approaching the greatest of mysteries.” - Carl Sagan

 

Thanks to Alissa Simon, HMU Tutor, for today's post.

This is the third of three posts on astronomy. (To access the previous two posts, click here and here). Also, a great thanks to Richard Johnson, amateur astronomer, for supplying all of the photos and much of the content for these astronomy blogs.

As we have prevoiusly discussed, the night sky tells us as much about ourselves as about the stars. For centuries, man has linked the complexity of humans with the starry heavens. As Henri Poincaré explains, “Astronomy is useful because it raises us above ourselves; it is useful because it is grand;...it shows us how small is man's body, how great his mind, since his intelligence can embrace the whole of this dazzling immensity, where his body is only an obscure point, and enjoy its silent harmony.” Since these images grab our attention and imagination, people continue to develop and enhance tools used in studying space. Last week we discussed the catalog created by Charles Messier, and this week we focus on another catalog created by Edward Barnard, a pioneer of astro-imaging.

M 42, The Orion Nebula. Photo credit: Richard Johnson.

M 42, The Orion Nebula. Photo credit: Richard Johnson.

Edward Barnard was born in Nashville, Tennessee. He received a fellowship to Vanderbilt University, where he spent four years, but never graduated. However he did receive an honorary degree, the only one ever awarded by Vanderbilt. He discovered ten comets during his time at Vanderbilt. He was then appointed to Lick Observatory in California, where he served four years. He then turned to the University of Chicago as a professor of practical astronomy. During these years he was responsible for identifying and cataloging the Dark Nebulae, which was later named the Barnard Catalog, numbering from 1 through 370 (although not all numbers in the sequence were used).

At one time, dark nebulae were thought to be holes in the Milky Way, but this is not so. The dark nebulae are actually interstellar dust clouds blocking or obscuring our view of the Milky Way. These dust clouds may be small, dusty star-forming regions, or they may be portions of larger dark lanes of galactic dust. Because of their darkness, they create interesting images. The following two images and nebula details were supplied by amateur astronomer Richard Johnson.

IC 434. Photo credit: Richard Johnson.

IC 434. Photo credit: Richard Johnson.

The Horsehead Nebula (Barnard 33) is a small dark nebula silhouetted against the glow of the emission nebula IC 434. Barnard 33 is the most interesting feature of a huge region of gas and dust situated 1,600 light years from Earth in the constellation Orion. Only by chance does the dark nebula resemble the head of a horse. But this coincidental appearance has led to its becoming one of the most photographed objects in the sky. The narrow patch of nebulosity extends from the leftmost star in Orion’s Belt, Alnitak. Barnard 33 is a dark globule of dust and non-luminous gas, obscuring the light coming from the moderately bright IC 434 nebula behind it. The red glow of IC 434 originates from ionized hydrogen gas. The Flame Nebula (NGC 2024) is about 900 light years from Earth, and is part of the Orion Molecular Complex, a star forming region that includes the Horsehead Nebula. The Flame Nebula is ionized and made to luminesce by the eastern most star in Orion’s Belt, Alnitak. NGC 2024 glows in a variety of colors, from yellow to orange, though the predominant hue is shell-pink. Additional dark gas and dust lies in front of the bright part of the nebula, and this is what causes the dark network that appears in the center of the glowing gas.

Barnard 72, The Snake Nebula. Photo credit: Richard Johnson.

Barnard 72, The Snake Nebula. Photo credit: Richard Johnson.

The Snake Nebula (Barnard 72) is about 5 light years across. It is located about 650 light years from Earth in the constellation Ophiuchus (The Serpent Bearer). It is a part of the Dark Horse Nebula.

To post a comment, click on the title of this blog and scroll down.