Starbirth in the Neighborhood

A Galaxy Blazes with Newborn Stars

Galaxies are huge collections of stars, gas, dust, black holes, and planets. The Milky Way is a good example of a spiral galaxy. It also happens to have a bar of gas and dust and stars across its center, and many places where stars are being born. It turns that when astronomers look at other galaxies, particular spiral galaxies (and many colliding galaxies), they also see regions of starbirth.

Hubble Space Telescope has been astronomy’s “go to” machine in space when astronomers want to look at something like a distant galaxy. This Hubble image shows the pinwheel (spiral) galaxy M83, which lies in our southern hemisphere skies in the constellation Hydra. It’s about 15 million light-years away, and, as you can see here, is ablaze with starbirth regions spread across 50,000 light-years of space.

The pink blobs are the starbirth nurseries sitting on the edges of dark dust lanes. They are churning out hot young stars that are extremely bright in ultraviolet light. The UV radiation heats up surrounding clouds, and they are what we see glowing in hot pink (in this image). Those hot young stars are busily evaporating nearby gas clouds with their UV light. They emit strong winds which also disrupt their nurseries. Eventually, the starbirth crêche disappears, revealing the newborn star.  Those hot young stars live short, energetic lives—perhaps existing only about 10 million years before exploding as supernovae. When they do die this way, the blast blows huge clouds of material out to space, blowing “bubbles” in space. HST has seen nearly 300 of these death bubbles. All this activity makes M83 a great place to study the dynamics of star birth, star death, and the contributions these events make to the galaxy.

It’s not just professionals who are studying this galaxy. M83 is being used as a target for citizen science, too. The idea is to come up with estimated ages for around 3,000 star clusters in this galaxy. The project is called Star Date: M83, a collaboration between the Space Telescope Science Institute and Zooniverse, creators of several citizen science projects including Galaxy Zoo, Planet Hunters, and the Andromeda Project (go to www.zooniverse.org to see the full list). The M83 project is launched on Monday, January 13, 2014. If you’re interested in participationg, visit http://www.projectstardate.org .

What will you be asked to do? You and others will use the presence or absence of the pink hydrogen emission, the sharpness of the individual stars, and the color of the clusters to estimate ages. Participants will measure the sizes of the star clusters and any associated emission nebulae. Finally, you and your fellow citizen scientists will “explore” the image, identifying a variety of objects ranging from background galaxies to supernova remnants to foreground stars.  If you’ve never done citizen science before, it’s quite interesting to participate in. I was part of Galaxy Zoo for awhile, and the people who ran that project provided all the information we needed to start classifying galaxies by their shapes.

M83 is a gorgeous object, and I think that people who study it (professional and citizen scientists) will come away with an amazing insight into the lives and deaths of stars in this distant galaxy.