Tag: Orion nebula

Desktop Project Part 19: Infrared Orion

By Phil Plait | April 13, 2012 10:29 am

[Over the past few weeks, I’ve collected a metric ton of cool pictures to post, but somehow have never gotten around to actually posting them. My Desktop Project — posting one of those pictures every day — is my way of clearing off my PC’s desktop, and also showing you some truly amazing stuff. Enjoy!]

The Orion Nebula is a perennial favorite for astronomers. It’s big (the size of the full Moon on the sky), bright (visible to the naked eye), and gorgeous (even binoculars show some wispy details). It’s also scientifically fascinating, since it’s the closest example of a big star-forming factory in the Milky Way. We get a fantastic view of it and can study it in incredible detail (see Related Posts below for lots more pix).

Because of all that, it amazes me that anything can provide a truly new view of this old friend… but then our eyes don’t see into the deep infrared. When you combine images taken with the Herschel and Spitzer space telescopes, which probe the cosmos in that part of the spectrum, the portrait they make is just stunning:

[Click to ennebulenate.]

As lovely as this picture is, there’s an important science story going on here as well. The stars you see embedded in those filaments and knots of interstellar material are actually very, very young: probably only a few million years old, and on the verge of becoming full-fledged stars like the Sun. They’re still enshrouded in the dust and gas disks in which they formed. Near the embryonic stars, of course, the dust is warmer, and farther out it’s colder. Spitzer and Herschel see in different parts of the infrared, where the different temperatures of dust emit light, so they probe both the inner and outer parts of the clouds.

Astronomers used Herschel to observe this nebula in 2011, taking a series of images over time. What they found is that the stars and their dust changed in brightness by as much as 20% very rapidly — over weeks, when it would be expected to take years! It’s not clear what’s going on behind this variability. I suspect the disks of material around the stars are clumpy, and the inner region has clouds that block the starlight, shadowing the outer region. As that happens, the cooler part of the disk dims, which is what Herschel saw. Other processes may be at work as well, but any ideas as to what they are have to be tested against the observations.

Which is precisely why we observe even familiar objects with telescopes sensitive to different kinds of light. Ultraviolet, infrared, visible, radio, X-ray — these are all parts of the spectrum controlled by different processes, so by observing different flavors of light we see the different engines creating them. It’s the combination of these varying views that gives us insight (literally, in this case, since we’re seeing inside a nebula!) into the physical mechanisms of various astronomical phenomena.

Even though the Orion nebula is one of the best studied objects in the sky, there’s still a lot to learn from it. And as long as we keep our eyes open, especially across the electromagnetic spectrum, then more and more of its secrets will be revealed.

Image credit: ESA/NASA/JPL-Caltech/N. Billot (IRAM)

Related Posts:

Orion’s got cavities!
A dragon fight in the heart of Orion (this is really awesome)
Spitzer sees star spew spurious spouts
A new old view of an old friend

CATEGORIZED UNDER: Astronomy, Pretty pictures

Orion's got cavities!

By Phil Plait | October 26, 2011 7:00 am

The Orion Nebula is perhaps the most famous gas cloud in the sky. And no wonder: it’s easily visible to the unaided eye, it looks fuzzy and diffuse even in binoculars, in small telescopes its shape can be discerned, and in long time exposures its beauty is devastating. The delicate wisps and tendrils, the bold colors, the odd shape… it’s got it all.

I’ve seen hundreds of pictures of it, and there’s almost always something new to see. But I don’t think I’ve ever seen a shot of it quite like this:

Isn’t that incredible? It was taken by Jesus Vargas (Astrogades) and Maritxu Poyal [click to ennebulenate]. Amazingly, it was taken with a telescope that had a lens only 10.6 cm (4") across! But the nebula is so bright that it doesn’t take a big ‘scope to get great images of it (though, to be fair, Takahashi makes very high quality ‘scopes).

What I like about this image is how obviously it shows that the nebula is actually a giant cavity in space. The actual cloud is far larger than what you see here, very dense and dark. But many stars are forming in the heart of the Orion Nebula, and a handful of them are massive and hot. Their ultraviolet radiation has flooded the interior of the cloud, eating away at it, carving out a huge divot light years across, and lighting it up. What you’re seeing here is more tenuous gas filling that cavity.

I love that. When I was younger I thought the nebula was just this diffuse puffery floating out in space, but reality is — as usual — more interesting, more profound, and more awesome than what we might first think. Images like this really drive that home.

Vargas and Poyal have several other images of this magnificent gas cloud, including this slightly wider field-of-view, one with different color filters, and one with a much wider field-of-View. These are all magnificent, and well worth your time looking at.

I’ve written about this nebula many times, as you might expect. Check out the Related posts links below for lots more info on this fantastic object.

Image credit: Jesus Vargas and Maritxu Poyal, used by permission.

Related posts:

A new old view of an old friend
The unfamiliar face of beauty
C-beams off the shoulder of Orion
A dragon fight in the heart of Orion

CATEGORIZED UNDER: Astronomy, Pretty pictures

A dragon fight in the heart of Orion

By Phil Plait | June 24, 2011 11:49 am

It’s very common to see familiar things in random patterns. We see faces in clouds, Jesus in a tortilla, and smiley faces everywhere. It’s so ubiquitous there’s a term for it: pareidolia.

So when I saw on reddit that people were talking about seeing an epic dragon fight in the Orion Nebula, I smiled. But then I saw the image, and that smile turned to pure amazement. Why? Because here’s the image:

[Click to ensmaugenate.]

Do you see the dragon on the left, wings outstretched, breathing fire, blasting it at the man on the right? He has a face, and I see his shoulder, back, and outstretched arm as well, as if he’s battling the dragon.

Let me be clear: this picture is real! Well, the dragon and face aren’t real — they’re more pareidolia — but the images in the nebula are actually there. You might see them more easily in this contrast-enhanced version, too.

Let me explain…

Read More

A new old view of an old friend

By Phil Plait | January 19, 2011 5:05 am

[Yes, that title is correct. Bear with me.]

I’ve seen the Orion Nebula approximately… well, how many times? Let’s see… um, carry the two… yeah, a gazillion times. You have too, probably, since to the unaided eye it appears as a star in the dagger hanging below Orion’s famous belt*. I’ve also seen it with binoculars and through telescopes ranging in size from dimestore junkers to a one-meter on a mountaintop. And yet, every new picture of it reveals something interesting… like this spectacular shot does:

Yowza. Click to ennebulanate, or get the orionormous 4000 x 3800 version. Or you can treat yourself to the 142 Mb 9000 x 8600 pixel version!

First, some stats: this picture is a combination of five separate images from the red to the ultraviolet (that last colored violet, actually), including a filter that sees just the glow from warm hydrogen (colored red in this image). The telescope used was a 2.2 meter in Chile. The nebula is pretty big — the full Moon would just fit inside this image — so the detail on this is truly stunning.

The nebula is a vast cloud of gas, both atomic and molecular, and dust located about 1350 light years away. It’s one of the largest star forming factories in the Milky Way, and what you see here is well over 20 light years across.

For years I figured it was just a diffuse glowing thing in space, but it turns out to be more complicated than that. Read More

CATEGORIZED UNDER: Astronomy, Pretty pictures

Astro info overload!

By Phil Plait | January 12, 2011 11:21 am

This week is the semi-annual meeting of the American Astronomical Society, the largest society of professional astronomers in the US. The January meeting is always huge, and always has a lot of news flooding from it like the collimated jet from a supermassive black hole. The big news stories I’ve written about the past couple of days have come from there, and I’ve been scrambling to keep up. But that’s proving to be difficult, so instead of my usual Pulitzer-level reporting of astronomy news, here are some links to stories that will probably interest you. And if you’re on Twitter you should be following the awesomeness that is Pamela Gay, aka StarStryder, as she writes live from the floor of the meeting (and blogs about it, too).

A very cool announcement from the orbiting gamma-ray observatory Fermi: thunderstorms on earth generate this high-energy form of light by creating antimatter. Yes, antimatter. This idea has been around for a while — I remember thinking about it years ago when I worked on the education and outreach for Fermi — but the scientists finally nailed down the specifics, and it’s pretty amazing. Not enough there to power a starship (and it might be hard to bottle it anyway), but still. Wow.

The Planck satellite is designed to look at the background radiation of the Universe in unprecedented detail. While it may not see any signatures by The Ancients (man, I’m ticked Stargate:Universe was canceled) it just released a whole lot of science, and Sean Carroll at Cosmic Variance has links to some of the science and scientific papers.

Read More

CATEGORIZED UNDER: Astronomy, Cool stuff, Pretty pictures

The unfamiliar face of beauty

By Phil Plait | April 5, 2010 8:00 am

The folks at Spitzer Space Telescope recently released a new image, and it’s a stunner:


Wow, what beauty! This picture shows the famous Orion nebula, one of the galaxy’s largest and most active star forming gas clouds. Spitzer is an infrared telescope, so blue here depicts light at 3.6 microns, roughly 5 times the wavelength your eye can see, and red/orange is 4.5 microns.

I could go on and on about the ethereal beauty of this image, about how we can actually see stars forming here, about why there are streamers and shock waves that sculpt this vast light-years long structure. But you can find me expositing at length on all those topics in other posts about other nebulae. That’s not the point I want to make here.

When I first saw the image, the email from JPL had the subject line "Colony of Young Stars Shines in New Spitzer Image", so I didn’t know what nebula it was showing. I simply clicked the link, and the image above popped up. I smiled when I saw it because of its beauty, at least at first. But after a moment I was puzzled. The nebula looked familiar, but for a brief moment I couldn’t place it. Then I focused my attention on the big cloud on the left, and my mind snapped into clarity.

hst_m42Any amateur astronomer on this planet can identify the picture at the left in a heartbeat. That’s an optical picture of the Orion nebula, one taken using visible light (the picture is by Hubble; click it to get more info and access to much, much larger versions). I’ve rotated the picture to match the one from Spitzer; you can see the same curved shock front going across the lower left corner, and the round comma-shaped cloud with a star near its center to the right. While the Hubble image is far more detailed (and colorful!) than what you see through an eyepiece, it still strongly resembles the view through a good telescope. But the Spitzer image…?

Have you ever met up unexpectedly with a friend you haven’t seen in five years? Maybe they grew a beard, or lost weight, or dyed their hair, or changed their clothing style. It’s the same person, clearly, but somehow different. It takes a second to recognize them, and when you do, it’s a bit of a jolt.

That’s exactly how I felt when I saw the Spitzer image (and like many an astronomer, I consider Orion an old friend). Spitzer’s image is just a little bit into the infrared, enough that details are different while the overall shape and features are the same. I knew it was my old friend, but it took me a moment to recognize its face.

And in many ways, like seeing that acquaintance after a few years, there were new things to learn, new ways to experience our friendship. The stars in the Spitzer image that are in the narrow bridge between the two halves of the nebula seem a bit more vibrant, a bit more obvious… as they should, since they are young stars in the throes of birth, and veiled substantially by dust. More stars overall are apparent in the image, since fainter ones can shine through the dust in the infrared, while their light is blocked by that dust in the visible. The streamers in the infrared image are more vivid, but the dust features less so, again as expected, but still somehow new and interesting.

In my travels I do happen to run across friends I haven’t seen in many years, and when I have time to actually sit and chat, I’m delighted when they have grown and done things they have previously not experienced. It brings a new side of them to light for me, lets me see them in a new way and appreciate them all the more.

And this is true on Earth as it is in the heavens. There are so many things to see in and above this world, and so many ways to see them! New eyes, new perspectives, new ways of seeing… it makes me always eager to find out what’s next, and to cherish what we already know.


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