Come Pet The Animals At The Galaxy Zoo

This 60-year light curve show the variable star Mira in Cetus rising and falling in brightness over time. The numbers at left are star brightnesses or magnitudes. Hundreds of observations submitted by variable star observers around the world went into creating the curve. Credit and copyright: AAVSO

Many of us plan new projects at the start of the year or at other important turning points in our lives. Back in 1982, when Star Trek: The Wrath of Khan was released and Dynasty was the rage on TV, I bought a new 11-inch telescope. Although there’s nothing wrong with being a tourist of the night sky, I wanted this purchase to help me go deeper, so I embarked on a new venture and joined the American Association of Variable Star Observers or AAVSO. As the name implies, members observe and estimate the brightness of variable stars, those suns whose light is not constant but changes weekly, nightly and even hourly. Observers submit their observations online to headquarters in Cambridge, Mass., which are gathered, organized and archived by the able AAVSO staff. The data is used by professional astronomers and other scientists around the world to help unravel the details of the behavior of these fascinating stars.

Before long, my first variable star charts arrived in the mail, and I soon found out how hard it was to track down a particular faint star. Like anything, after repeated practice, I learned to navigate my way to almost any star of interest,  make a brightness estimate, and send off a data point to the AAVSO. It’s a small but satisfying way to make a scientific contribution.

Not that variables aren’t intrinsically interesting – some of the most captivating and exciting ones are supernovas and novas, which can appear any night out of nowhere. Then there are the “familiar faces” like Mira, Algol and others that I routinely check in on as one might pay a visit to a friend.

The spiral galaxy M101. Galaxies are classified broadly as spiral, elliptical or irregular. The Milky Way is a spiral galaxy with prominent arms and regions of new star birth. Credit: NASA/ESA

With 2011 wide open, you may want to consider making a scientific contribution of your own. It doesn’t have to be variable stars necessarily. With the Internet and the ability to rapidly share enormous amounts of information, there are lots of areas that a complete beginner can jump into and get involved.

Let’s start easy.  Ever heard of the Galaxy Zoo 2? It was launched in 2007 with the aim of getting the public to help classify a million galaxies photographed by the robotic telescope in the course of the Sloan Digital Sky Survey. Back then, you logged on, looked at galaxy photos and clicked to classify the type – spiral or elliptical. If spiral, you noted the direction of the arms. The program took off with lightning speed, receiving 70,000 classifications per hour within a day of launch. All told, 150,000 people like you and me participated in the survey. And here’s what astronomers discovered: ordinary Joes and Janes could classify a galaxy as well as the professionals.

The elliptical galaxy NGC 4458 in Virgo. Ellipticals are typically oval-shaped, smooth and featureless compared spirals. They also contain a greater number of older stars. Credit: NASA/ESA

In Galaxy Zoo 2, the project folks kicked it up a notch and started asking participants additional questions about galaxy shape, color, whether it has a “peculiar” appearance or sports a bright bar in its mid-section. Volunteers rose to the task and helped make more than 60 million classifications in a span of 14 months. Thanks to their efforts, there have been a few surprises for the professionals. Astronomers used to assume that a red-colored galaxy was always an elliptical; thanks in part to the public’s input, they’ve since learned that up to a third are spirals. More discoveries await your participation.

Click on How to Take Part and you’ll be presented with a clear, interactive tutorial loaded with examples of what to look for. As soon as you’re done familiarizing yourself with galaxy details, just click on the CLASSIFY link at the bottom of the page and you’re ready to roll.

Van Arkel's peculiar blue haze. Credit: Sloan Digital Sky Survey

I gave it a try and had two galaxies classified in only a few minutes. Be sure to note if you see anything peculiar in or near the galaxy. Hanny Van Arkel, a Dutch schoolteacher and Galaxy Zoo volunteer, asked about a strange blue haze below one galaxy, prompting follow-up observations with both orbiting and ground-based telescopes. And don’t worry about making a mistake. Lots of other people will see your galaxies and submitting their classifications. Multiple classifications are ideal, because they allow astronomers to pick the one most or all agree upon.

Galaxy Zoo 2 is going far deeper than the original survey, which covered only relatively nearby galaxies. Its targets include some of the most remote galaxies ever photographed by the Hubble Space Telescope and take us back to the early days of the universe, when galaxies had different colors and appearances compared to galaxies in the current era.

The third basic galaxy form is represented by the dwarf irregular galaxy NGC 1427A. Credit: NASA/ESA

Ready to become a galactic researcher while sipping a cup at the computer? Give it a shot. You’ll have the satisfaction of making a contribution to astronomy while learning all kinds of wonderful things about the biggest star systems in the universe.

I’ll be heading back to the Zoo right after a shower. See you sometime in the distant past 😉