Enjoy this guest post about the constellation Orion by astrophotographer David Rankin. This week, Orion harbors an awesome secret … a witch!
By now, hopefully, you should be able to spot Orion in the winter sky.
When you walk out just after dark, Orion’s bright figure towers over you to the south … It’s the Witch Head Nebula.
See the photo below. Can you make out the shape of a witch’s head? Do you see a hat, a large nose, a cheekbone, and a protruding chin?
The witch stares back at the bright star Rigel as though it were her own evil creation.
The Witch Head Nebula
Do you see the witch’s profile? Credit: astrophotographer David Rankin Technical mumbo jumbo: shot with a Canon 6D, 200mm F2.8 lens at F4, 12 exposures at 300 seconds each
You may look at this photo and wonder, What in the world is going on here? Well, nothing in the world is going on here. The goings-on are happening about 900 light-years away! That is 900 years traveling at the speed of light. Light travels pretty fast, by the way, about 186,000 miles in one second. So this photograph is actually a representation of what the Witch Head Nebula looked like 900 years ago! No big deal.
There are a lot of gas clouds in outer space, and astronomers cryptically refer to them as “nebulae” (the Latin word for “clouds”). The light coming from the very bright star Rigel is passing through this gas and splits up, somewhat like that Pink Floyd poster some of you may have seen. Light is made from all colors of the rainbow, but the warmer colors (orange, red) tend to pass through the gas while the cooler colors (blue, purple) tend to bounce off the gas, making the nebula appear blue. Our sky is blue for the exact same reason. This type of nebula is called a reflection nebula, and we live inside of one!
Where is she?
To gain a little perspective, the image below shows the location of the Witch Head Nebula inside of Orion. Easy to spot with the naked eye, but far too faint to be seen without the help of digital photography.