Category Archives: astronomy research

'Casts, astronomy, Astronomy outreach, astronomy research, astrophysics, physics, space exploration

Take a Journey into Outer Space

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Or, Listen to Eminent Scientists Talk about It

I just got a note about a very cool-sounding event that will be taking place on March 16, 2011. It’s called “A Journey into Outer Space” and presents a slate of names many folks have heard of, talking about their science and the future in space. The event features the BBC’s Professor Brian Cox, who will speak about the Large Hadron Collider and dark matter; Charles Simonyi will describe exactly what it’s like to be aboard the International Space Station; Colin Pillinger (of Beagle 2 fame) will ask if there’s anyone else out there; the inimitable Richard Holmes will chart the history of humanity’s fascination with space; Astronomer Royal Lord Martin Rees will talk about everything Big Bang-related; and Rick Stroud will chair. The event is being put on by a group called IntelligenceSquared.

Now, if you were attending this event in person, there’d be a cover charge — and a pretty reasonable one at that, of only £30.00 for regular admission or £15.00 for students. (About $48.00 USD, or €34.00. Go here to convert that to your local currency.)  I think that would be well worth it, if I lived in the area. However, I don’t and so don’t lots of other people. But, the folks at IntelligenceSquared have solved that problem.

For those unable to attend the event in London in person, the organizers have a live stream available, which offers a fantastic interactive alternative for viewerers. Watching live online is free for everybody. You simply have to  create a free account with your email and a password, and then enjoy the event. All the details are on their web site, linked above. Note that the time of the event is given in London time, so be sure and figure out what time that will be in YOUR time zone (and remember, some of us go on Daylight Savings Time this next weekend, so don’t forget to take THAT into account, too).

During the event, live-stream viewers will also be able to discuss the questions raised using our comment tool (including Facebook and Twitter), and vote on the motion if it’s a debate. The IntelligenceSquared folk will forward the best comments on Rick Stroud, who will then ask the panellists to answer the questions.

The organizers have a Twitter account and hashtag, so check out their tweets at:  #iq2space

Many of the panelists are well known to folks in the blogosphere, and it should be an interesting time. And who knows, you might find yourself asking the Astronomy Royal or Professor Brian Cox (or any of the other panelists) a question of your own.

astronomy, astronomy news, astronomy research, Infrared astronomy, spitzer space telescope

Come With Me to the Starry City

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And View it in Waves of Infrared Light

Astronomy takes you out there, thataway — and takes your breath away with cosmic visions of loveliness.  If it weren’t for the tools of astronomy that populate our spaceship of exploration, we’d still be seeing the universe in the equivalent of “black and white” TV of mid-last-century.  Those tools, like the Spitzer Space Telescope, with its infrared-sensitive detectors, open up the multi-wavelength universe and let us see things we weren’t able to see before.  Like the North American Nebula, in the constellation Cygnus, the Swan. Spitzer has just released some gorgeous imagery of this formerly mysterious region of space.

The first human to see the North American Nebula was William Herschel, back in 1786. It was merely a smudge to him, as it would be to anyone with a similar type of small telescope like he used.  I once tried to look at this nebula through a pair of fairly strong binoculars and through an 8-inch telescope, and it was faint, indeed. But, the shape of the nebula could be made out — it really does look like the outline of the North American continent.  However, this have changed since Herschel’s day. Today, we have telescopes and spacecraft that can look at wavelengths of light beyond the visible. Those have changed our perceptions of the cosmos.

Actually, what’s really changing is what we’re now able to see.  We’re detecting MORE of what’s in the nebula.  So, for example, we’re seeing infrared radiation given off by hot gas, for one thing. Inky black dust features seen in visible light are also heated, and they start to glow in the infrared view.

Different colors display different parts of the spectrum in each of these images. In the visible-light view (upper right) from the Digitized Sky Survey, colors are shown in their natural blue and red hues. The combined visible/infrared image (upper left) shows visible light as blue, and infrared light as green and red. The infrared array camera (lower left) represents light with a wavelength of 3.6 microns as blue, 4.5 microns as green, 5.8 microns as orange, and 8.0 microns as red. In the final image, incorporating the multi-band imaging photometer data, light with a wavelength of 3.6 microns has been color coded blue; 4.5-micron light is blue-green; 5.8-micron and 8.0-micron light are green; and 24-micron light is red.

This swirling landscape of stars is known as the North America nebula. In visible light, the region resembles North America, but in this new infrared view from NASA's Spitzer Space Telescope, the continent disappears. Where did the continent go? The reason you don't see it in Spitzer's view has to do, in part, with the fact that infrared light can penetrate dust whereas visible light cannot. Dusty, dark clouds in the visible image become transparent in Spitzer's view. In addition, Spitzer's infrared detectors pick up the glow of dusty cocoons enveloping baby stars. Clusters of young stars (about one million years old) can be found throughout the image. Slightly older but still very young stars (about 3 to 5 million years) are also liberally scattered across the complex, with concentrations near the "head" region of the Pelican nebula, which is located to the right of the North America nebula (upper right portion of this picture). Some areas of this nebula are still very thick with dust and appear dark even in Spitzer's view. For example, the dark "river" in the lower left-center of the image -- in the Gulf of Mexico region -- are likely to be the youngest stars in the complex (less than a million years old).

In the bottom two images, only infrared light from Spitzer is shown — data from the infrared array camera is on the left, and data from both the infrared array camera and the multi-band imaging photometer, which sees longer wavelengths, is on the right. These pictures look different in part because infrared light can penetrate dust whereas visible light cannot.

If you look back up at the “visible light” image of the nebula, you’ll see that it’s tough to make out those baby stars and the dusty cocoons where they formed. This is because they’re hidden by dark clouds, which are transparent to infrared light. This lets us peek behind the veil of gas and dust that hides star birth from us.

Baby stars are just part of the scene in the Spitzer image. We can see everything from the stellar cocoons where stars form to newborn stars sporting active jets to so-called “young adult” stars that are becoming more stable, and more capable of sustaining planetary systems.

There’s more to discover in this region of space. Not even Spitzer could reveal all the North American Nebula’s secret, hidden objects. Some of its clouds are just too dense for infrared to penetrate.  And, Spitzer now has no coolant left to chill down its detectors, so some of the longest wavelengths of infrared that it used to be able to detect are no longer available to it. But, that’s not stopping astronomers from studying these images and data. There’s still much to  learn from these observations. Stay tuned!