Orion Exploration

Orion from the Isaac Newton Group of Telescopes (Simon Tulloch and Nik Szymanek)

In the last installment, I started a discussion about the Orion Nebula. Since it’s such an interesting place, I think I’ll talk about it a little more — it’s got so much to explore!

Astronomers refer to the Orion Nebula as an HII region because it is largely made up of hydrogen gas (H₂), with a dash each of helium, oxygen, nitrogen, and traces of other elements. When the Orion birth clouds are are heated by nearby stars, they glow (emit light) in various colors — transforming it into a glowing emission nebula. The starbirth nursery may look serene in this image, but the nebula is an incredibly active place. Stellar winds scoop out caverns around the newborns, jets of superheated gas streak out from the stars, and lumpy-looking cloud textures are carved out by the combined actions of jets and winds. In the center of the nebula lies a cluster of newborns less than a million years old. None of these stars are likely to have planets — yet, and even if they did, their brightness would make it extremely difficult to find the tiny planetary pinpoints. Yet, there are things forming here that we can spot if we use an infrared-sensitive instrument to do the searching.

Orion as seen by HST

Hubble Space Telescope gazed at the central cluster of stars in the Orion Nebula with its optical camera and infrared NICMOS instrument, revealing bright stars in visible light — and hidden among them — about 50 of the so-called “substellar objects” that we all know as brown dwarfs glowing in infrared light. They’re the bright star-like objects in the image on the right. These are too cool to be stars, too hot to be planets and difficult to see, unless you happen to have infrared eyes.

Could our own neck of the galaxy have looked like this about 5 billion years ago? If so, when you gaze at the Orion Nebula, you may very well be see what baby pictures of the Sun and its stellar siblings could have resembled, if there’d been anybody around to do the looking!

Blushing Orion

When you go out to find Orion later this year, it’s a safe bet that what you see through your binoculars or small telescope (or even the naked eye) will be limited to optical wavelengths of light — that is, the light your eyes are most sensitive to. That makes sense, since that’s what “optical” means. But, what if you had eyes that were sensitive to infrared light — specifically to the 1.2 to 2.2 micron infrared wavelength range, and you could zoom in on the constellation Orion and the nebula that lies just beneath the three stars that make up the belt of Orion? You might see something that looks like this 2MASS image.

I’ve discussed the Nebula in this blog before — it’s one of my favorite places to study in the winter sky (and is a familiar summer sight for southern hemisphere stargazers). The nebula contains one of the closest star formation regions in our neck of the galaxy. Small wonder that it’s one of the most heavily studied areas of the sky. Every major observatory ranging from the likes of Hubble Space Telescope to the smallest amateur facility has a picture or some data set relating to this nebula.

Orion as seen by the 2-Micron All-sky Survey (2MASS)

The visible part of this nebula is only a small part of a huge cloud of gas and dust spread out across the region of the galaxy where the nebula and its “trapezium” of newborn stars inhabit. The whole complex is called the Orion A Molecular Cloud and it is a huge storehouse of containing the raw materials for star formation. Newborn stars already formed in this “stellar nest” are lighting up the rest of the cloud, which enables us to see it from across 1,500 light years of space.

This 2MASS infrared view of the Nebula looks quite different from the many colorful optical light images we’re all used to seeing in books, magazines, and spread out across the planetarium dome. The light we see with our eyes and in those optical photos is given off by glowing gases in the nebula, or reflected off of dust grains. Those gas and dust clouds hide other objects in the nebula. In infrared light the obscuring clouds of dust are more transparent, allowing us to see deeper into the Orion Nebula and revealing the otherwise hidden stars and other objects scatted throughout the region. None of the reddest objects in this picture can be seen in visible light!

If you’d like to look at other familiar sky objects with an infrared eye, take a look at the 2MASS web site. What you see will give you a greater appreciation for how the universe looks through infrared eyes!

Space Art

Image credit: Chris Butler, sold through NovaSpace Galleries

Well, last time I wrote, it was about space music. Now it’s time to explore a little space art. Astronomy and space travel and exploration have inspired a lot of paintings and digital masterpieces over the years. Some of the best artwork I’ve seen is available through a company called NovaSpace Galleries. I’ve always been fascinated with the ways that these and other artists interpret space and astronomy themes.

I know where they get their inspiration: the telescope, out under the starry skies, and from the images we get from our telescopes and spacecraft. Some of those “real” images almost seem like space art — like the one below, showing two interacting galaxies, taken using the Hubble Space Telescope.

Galaxy as seen by HST

With such wonderful images from the realm of science, it’s no small wonder that the realm of space art is rich and varied. Artists take their inspiration from any part of the cosmos, using space exploration and observation to spin out gorgeous fantasies based in reality. I love to browse space art — it takes me to places and times and events that I can never go on my own.

There are plenty of good places to go view beautiful space art on the web — beginning with the International Association of Astronomical Artists (IAAA), and their website at: IAAA.org., and of course a site dedicated to the Father of Space Art, Chesley Bonestell (Bonestell Space Art. Next time you’ve got a free moment on your hands and a little urge to explore space on the Web, check out the space artists!