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All posts for the year 2005

Andromeda Galaxy, Courtesy National Optical Astronomy Observatory

Andromeda Galaxy, Courtesy National Optical Astronomy Observatory

There IS more to the universe than meets the unaided eye. That’s the story I told in one of my planetarium shows, “More Than Meets the Eye” and I’m stickin’ to it. Here’s why: each time you shift wavelength “regimes” and look at the sky, you learn more about what makes objects tick. Take the Andromeda Galaxy for example (since it’s high overhead in northern hemisphere skies these early winter evenings).

This is the typical picture we see of Andromeda. Beautiful, and since it’s the closest spiral galaxy to us, a great example of the general structure of spirals. However, if you look at Andromeda in the infrared, the image changes dramatically.

Spitzer view of Andromeda (infrared)

Spitzer view of Andromeda (infrared)

Suddenly the spiral rings pop into view much more clearly. The dust regions are glowing, and where there’s warmed dust, there’s action going on. In this case, the action comes from hot stars (and other hot events) warming up the surrounding clouds of dust.

Another Spitzer view of Andromeda

Another Spitzer view of Andromeda

You can read more technical detail about this astonishing “infrared makeover” of Andromeda Galaxy at the Spitzer Newsroom, but for now, just compare and contrast the visible-light image with the two infrared images of our nearest spiral neighbor. Lovely, isn’t it?

Courtesy Hubble Space Telescope

Courtesy Hubble Space Telescope

I am a sucker for starbirth regions. This past week while working on the Griffith Observatory exhibit project, I was browsing around various observatory websites, looking for smacking good images of starbirth regions. While we were looking for some specific objects inside stellar nurseries, I couldn’t help but be dazzled by this one (although we ended up not using it).

What we’re seeing here is a snapshot in time well into the birth process of hot young stars, and as an added bonus, a scattering of smaller young stellar objects which haven’t quite started to convert hydrogen to helium in their cores. All the newborn objects in these clusters are embedded in their birth cloud of gas and dust, giving us a pretty nice look at several stages in the formation process of stars. The dark dust clouds could be harboring more incipient stars, but they’re being eaten away by radiation from the brightest nearby stars. So, if there ARE any about-to-be-born stars in the clouds, their gas and dust supply may get vaporized by the hot winds blowing off the older stellar siblings.

To read more about this beautiful starforming region, go here.

The stars in this image are more massive that our Sun. But, you kinda have to wonder what our own neck of space looked like when the Sun was being born. AS we all know, it formed about 4.5 billion years ago in a cloud of gas and dust, probably along with a bunch of stellar siblings.

As it turns out, the Spitzer Space Telescope has a great image of sunlike stars in formation. Check it out.

NGC 1333 as seen by Spitzer Space Telescope

NGC 1333 as seen by Spitzer Space Telescope

This is quite a bit more interesting because this could well be what we looked like, way back when. The wisps of material are shock fronts in the stellar birth cloud that are carved out by jets streaming from the stellar newborns. What we’re seeing here is an infrared view, not what our eyes would detect. But, Spitzer excels in looking at the glow of infrared radiation emitted by hot young objects that are warming up the nearby clouds of gas and dust. If you want to look at this picture in more detail, go here and click on one of the larger images.

See why I love these regions? They just excite the eye—and the imagination!