IF YOU KNOW NOTHING about astronomy and galactic formation and nebulae, you still probably know about the Horsehead Nebula. The gorgeous image of that mass of dirt and debris above was taken by Ken Crawford in 2011. He took this photo from his backyard observatory in Rancho Del Sol Camino, the image taking twenty hours of exposure and seven different filters!
He believes this image is popular because of the recognizable shape of the nebula and the striking astronomical features. “The glowing pink/red hydrogen provides a beautiful back drop to this amazing region of the deep sky,” he said.
I agree with Mr Ken Crawford: looking at the image—as a painting and starting in the lower left corner, the movement from the cold blue up through the neutral gray in the center and on to the warm reds of the top is stunning. That both of these latter two areas are punctured by the spiked white light of a star/galaxy only heighten the dramatic horse-like image of the massive cloud of stellar debris in the center.
The Horsehead Nebula is extraordinary—beautiful beyond belief, perhaps forever beyond grokking—to the human consciousness and yet so ordinary that if the Universe had a mind of its own it might not ever get around to noticing it …
The astronomical picture of the day
Crawford, who owns a carpet business, became an amateur astrophotographer in 2001. This is a specialized type of photography for recording images of astronomical objects and large areas of the night sky. Besides being able to record the details of extended objects such as the Moon, Sun, and planets, astrophotography has the ability to image objects invisible to the human eye by long time exposure.
Photography revolutionized the field of professional astronomical research, with long time exposures recording hundreds of thousands of new stars and nebulae that were invisible to the human eye, leading to specialized and ever larger optical telescopes that were essentially big cameras designed to collect light to be recorded on film.
The Horsehead nebula appears dark because of the dust in the neighbouring area, with the bright spots at the base marking newly formed or forming young stars.
Astrophotography is a large sub-discipline in amateur astronomy, where it is usually used to record aesthetically pleasing images rather than for scientific research.
Astronomy Picture of the Day (APOD) is a NASA-backed website with a different image or photograph of the universe featured each day. The pictures and descriptions are often related to current events in astronomy and space exploration.
When APOD began on June 16, 1995, it received only fourteen page views on its first day. As of 2012, it is estimated that there have been over 1,000,000,000 views.
Photo: Galaxy NGC660
Young stars in the process of forming
The dark cloud of dust and gas is a region in the Orion Molecular Cloud Complex where star formation is taking place. It is located in the constellation of Orion, which is prominent in the sky on winter evenings the northern hemisphere. This stellar nursery can contain over one hundred known kinds of organic and inorganic gases as well as dust; some of the latter is made up of large and complex organic molecules.
“The Horsehead Nebula is a diffuse dark nebula found in the Orion Molecular Cloud Complex in Orion constellation. It is a dark cloud composed of dust and gas where star formation is taking place. The nebula is also known as Barnard 33, and is located in emission nebula IC 434. It is approximately 1,500 light years distant from Earth.
The swirling clouds of gas and dark dust are lit by a pinkish glow of hydrogen gas located behind the nebula and ionized by the nearby bright star Sigma Orionis, which is in fact a five-star system [that] illuminates the entire region.
The brighter star visible in this area of the sky in images is Zeta Orionis, but it is located in the foreground and not related to the Horsehead Nebula.
The nebula formed from a collapse of an interstellar cloud of material and appears dark mainly because of the thick dust in the neighbouring area, with the bright spots at the base marking hidden protostars, newly formed or forming young stars.” (Constellation Guide)
The red or pinkish glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. Magnetic fields channel the gases leaving the nebula into streams, shown as streaks in the background glow.
The heavy concentrations of dust in the Horsehead Nebula region and neighboring Orion Nebula are localized, resulting in alternating sections of nearly complete opacity and transparency. The darkness of the Horsehead is caused mostly by thick dust blocking the light of stars behind it. Bright spots in the Horsehead Nebula’s base are young stars just in the process of forming.
The article above is adapted liberally—would I adapt any other way?—from several entries in Wikipedia. I did this rather that write something original because I wanted this image on my site with some kind of explanation and I am unqualified to have any kind of opinion or write any kind of original commentary.
Photo: Heart Nebula IC1805
Ken Crawford mini-gallery
The Horsehead Nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory. It is approximately 1500 light years from Earth. Today, it is one of the most recognizable images of our universe that is not a part of our solar system!
In 2004, Crawford was one of the principle founders of the Advanced Imaging Conference held every year in San Jose; he has served as President of AIC since 2007. In 2008, he was invited to sit on the NASA Astronomy Picture of the Day site, with many of his images appearing as the picture of the day. I have included four amazing photos from his portfolio in this article.
This last image should need no title to be recognized: just look up on any cloudless day. If you have read this far, you need to visit Ken Crawford’s website, Imaging Deep Sky.