Category Archives: Orion

american astronomical society, Gemini Observatory, Orion, Orion Nebula

Bullets of Star Formation

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Clumps of Supersonic Gas Point Back to Hot Young Stars

 

 

This image reveals exquisite details in the outskirts of the Orion Nebula. The large adaptive optics field-of-view (85 arcseconds across) demonstrates the system’s extreme resolution and uniform correction across the entire field. The three filters used for this composite color image include [Fe II], H2, and, K(short)-continuum (2.093 microns) for blue, orange, and white layers respectively. The natural seeing while these data were taken ranged from about 0.8 to 1.1 arcseconds, with AO corrected images ranging from 0.084 to 0.103 arcsecond. Each filter had a total integration (exposure) of 600 seconds. In this image, the blue spots are clouds of gaseous iron “bullets” being propelled at supersonic speeds from a region of massive star formation outside, and below, this image’s field-of-view. As these “bullets” pass through neutral hydrogen gas it heats up the hydrogen and produces the pillars that trace the passage of the iron clouds.
Principal Investigator(s): John Bally and Adam Ginsberg, University of Colorado and the GeMS/GSAOI commissioning team; Data processing/reduction: Rodrigo Carrasco, Gemini Observatory; Color image composite: Travis Rector, University of Alaska Anchorage. Image Courtesy: Gemini Observatory/AURA
The universe is not a static place. Things change all the time. So, the more often you look at an object or process in the cosmos, the more information you’ll get about how it changes over time. Astronomers take advantage of this to get what you might call a “time varying” view of something like the Sun or a planet or a star-forming region (for example). The process gets very interesting when they use newer technology to study something that seems familiar, like the Orion Nebula.

The Gemini Observatory observed a region of the Orion Nebula in 2007 and imaged what are called “bullets”. These almost look like tunnels through the clouds of gas and dust that make up the nebula. They are actually strong winds blowing gas off of massive stars at incredibly high speeds. As these “wind bullets” speed out, they carve out these tubular wakes as much as a fifth of a light-year long.

Those original images were some of the best taken of this region at the time, and they showed dynamic action surrounding hot young stars in the nebula.

Now, the Gemini Observatory has studied these again, this time using an a technology called adaptive optics and laser guide stars to gain a sharp clear image of these bullets in the Orion Nebula. The laser guide stars are artificial stars that are made using a special laser that shoots into the sky and provides astronomers a guide to aim at. They read those stars and use what they see to “adapt” the telescope system to account for the atmospheric aberration between the telescope and the sky. The process provides very clear, almost Hubble-like images, but from the ground.

The new images show more detail and, if you look closely between the originals and the new ones, you can make out a little bit of dynamic motion in the clouds themselves.

Check out the new image here, and then go over to the Gemini page and look at a previous image of the bullets — you can see clear improvements that are giving astronomers a great new tool to check out the Orion Nebula better than ever before.

 

 

dark skies, HII regions, molecular clouds, Orion, starbirth, stars

Orion’s Slipping Away

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Check it Out Tonight

A quick perusal of my favorite blogs this morning took me to Phil Plait’s Bad Astronomy blog, where he’s posted pictures he took last night of the constellation Orion as a sort of backdrop to the Space Shuttle and the International Space Station. That reminded me (as if I needed it, really) that the onset of northern hemisphere spring (southern hemisphere autumn) signals a long farewell to the starshow that is the constellation Orion. In another few weeks, my favorite winter star pattern will be gone for a few months, to be replaced at night with the stars of spring and summer.

Why do I like this constellation? Well, for one, after the asterism of the Big Dipper, it’s one of the most recognizable star patterns in the nighttime sky. I also like to think that it’s kind of a gateway constellation into other great things, like starforming regions. And, once you get a taste of seeing those, you might want to wander around other parts of the sky, getting acquainted with the sights that so excite both amateur and professional astronomers.

Who knows? If more people got interested in astronomy because of Orion, they’d understand why we spend money to pay astronomers to study the cosmos and report back on what they find. It’s not just because it looks pretty and we get great pictures. We also learn something about how the universe works, and since we’re part of the universe, it means we learn more about our own planet and how it formed back a few billion years ago.

The Orion Star Nursery

So, getting back to this star nursery… it’s called the Orion Nebula, and if you go out tonight (or whenever it’s clear) and look below the three belt stars (or above them or next to them, if you’re in the southern hemisphere) you will see a faint fuzzy patch that looks kinda greenish-gray. That’s it. The place where stars are being born. The center of the cloud is dominated by a quartet of bright young stars called the Trapezium. They’re blasting out light and ultraviolet radiation. That UV is eating away at the clouds of gas and dust that were once the birthplace of these stars. What’s left is glowing from the energy being pumped out by these stars.

Hubble Space Telescope took a closeup look at the Trapezium. It found many more hot young stars, some brown dwarfs, and some stars with protoplanetary disks (which could turn into planets in a few millions of years if they aren’t already) around them.

So, for the next couple of weeks, while there’s still time, go out not too long after sunset and check out the constellation Orion, and see if you can find the Nebula. There aren’t too many places like it that we can see with the naked eye from the comfort and privacy of our backyards. If you’d like to read more about the Orion Nebula, start here, and then go here for some Hubble views of it. Check out Spitzer Space Telescope’s look at it, and then round out your multi-wavelength tour of the nebula by visiting the Chandra X-Ray Observatory view.