Trying to figure out that a random green blob of gas is a light echo was anything but easy. In this comic book, we try and tell the story of what it was like for the people involved and how exactly astronomy – in its not exactly Indiana Jones fashion – can be an amazing adventure. The project was written largely by a team of volunteers from CONvergence, and the art is by two amazing students here at SIUE.

Here is what we wrote over on the Galaxy Zoo Blog:

line art: Elea Braasch, color: Chris Spangler

This past Monday, at about 8pm Central (GMT -4), a Voorwerpish webcomic was delivered to Sips Comics for printing. Tuesday morning we got the page proofs, and now, one by one, they are being made into full color reality.

We could say a lot of things right now: We could tell you about playing round robin with the script, digitally passing it from person to person under the guidance of Kelly, sometimes into the wee hours of the night. We could tell you about watching the art come to life; transforming from line drawings to fully rendered pages in the hand of our artists Elea and Chris. We could tell you how many pencil tips were broken, and how many digital files grew so big our computers crawled.

We could talk a lot, but instead, let us invite you to join us for the World Premier and share with you a few images.

You’re Invited to a World Premier

• Time: 3 September, 10pm Eastern (GMT -5)
• Online: via Hanny’s Voorwerp Webcomic or via direct UStream Link
• In Person: At Dragon*Con
  Crystal Ballroom
  Hilton Atlanta
  255 Courtland Street NE
  Atlanta, GA

Come meet the artists, hear a brief talk by Bill, and generally revel in the Voorwerp’s awesomeness.

And come dressed as a Voorwerp for a chance to win a prize for best costume!

See you in Atlanta?

Pamela, Hanny, Bill, Kelly, Elea and Chris

The truth is, the cluster and our Sun had a falling out.

Once upon a time, somewhere in our galaxy, our Sun’s atoms were part of a giant molecular cloud. Approximately 7 billion years ago, that molecular cloud was bumped. Exactly what did the bumping no one knows. That anonymous bump so shocked the dark molecular cloud that in recoiled and collapsed in on itself. At first this inward spiral wasn’t at all dramatic, and an imaginary space traveler looking at this shocked cloud with her imaginary eyes might not have perceived the motion. Over time, however, momentum built up, and the collapse gained speed, with the densest parts of the cloud pulling themselves into fragments, as more ethereal parts were left behind to collapse more slowly. In one of these collapsing regions a womb of gas and dust that was neither too big nor too small began to glow as a single star exhaled its first breath of heat. As it grew and began to illuminate its surroundings, a disk formed; a disk containing just enough stardust to someday form 8 planets and a lot of harder to categorize smaller bits.

While this star, which would come to be called “The Sun,” was busy forming, its nursery mates were similarly busy growing, glowing, and in some cases even going an extra step and exploding. This stellar nursery was filled with screaming stars that wept radio waves and threw off high energy jets as they tried to find their way onto the main sequence. While these stars wailed and grabbed at matter, they also traveled as a pack around the galaxy. While we can’t do more than guess at the Sun’s original orbital position, we know that today it takes about 135 million years for the Sun to orbit the galaxy. Let’s assume for a minute that the Sun emerged from the center of of that cluster. This would put it in a position to watch some of its nursery mates race ahead around the galaxy, take less time to orbit, while other of its nursery mates slowly fell behind, taking longer to orbit (and a few just explode themselves into oblivion as supernovae). After a few orbits and a few hundreds of millions of years, these differences in speed caused the fastest (and slowest) stars to fall out of the cluster, as their positions no longer made it possible for the casual observer to match them up with their cluster of origin. Over time, differences in orbital velocities drew more and more of the stars away from their siblings. Eventually, it became impossible to tell exactly which stars made up those sibling stars to the Sun.

The Sun, like its sisters and brothers, simply fell out of the cluster as it raced around the galaxy, just as a runner might fall away from the pack.

We are an orphan system, alone in the galaxy. Unlike the majority of stars, our Sun has no companion. Having escaped the chaos of our home, we are now simply alone.

Here is what has me excited. In a new paper in Astronomy and Astrophysics (which my Uni doesn’t get) with Pierre Kervella as lead author,  the distance to a Cepheid variable has finally been accurately measured in a method so simple I can’t believe it wasn’t done before. The binocular-bright Cepheid RS Pup is embedded in a nebula. As it’s light varies, it causes the dust and gas to also vary in brightness. By measuring how long after the star varies in brightness the blob of gas and dust varies in brightness, it is possible to tell how far apart the star and blob are located (sort of like measuring the distance between two cities based on how long it takes to drive between them going 100 km/hr). The next step is to measure the angle on the sky between the two. This gives us one angle and one side on a triangle. Everything else is than calculatable – including the distance from us to them.

Beautiful. Clean. Simple. I wish I knew why no one did this before. (Hopefully that’s addressed in the paper.)

The other thing the press release doesn’t do is tell me if these new results significantly changed our understanding of our place in space. Cepheid variable stars are one of the standard  candles used to measure the distances to other galaxies and to calibrate the supernovae distance scale. If it turns out that we misplaced the Cepheids it will rescale things a bit. We shouldn’t be off by more than a few percent (we have some not totally accurate ways to measure distances today with bad parallax measurements), but still… It will be interesting to know how close we got by averaging a whole bunch of imperfect measurements.

Once I get my hands on the paper, I’ll let you know.

Here is a quote from Toru Yamada, one of the observing team’s members: “We just wanted to look at something beautiful.”

I love honestly.

Every astronomer has dreamed of doing this (and many of us have). You are at the scope – some multi-meter behemoth capable of peering into the ultimate galactic hearts of darkness – and you just want to take a picture of some pretty binocular object. Ethics generally requires that we don’t. Our time is allocated based on how much time we need to observe set objects to obtain specific scientific goals. When we are at the telescope controls, we had best be chasing science if we ever want to get telescope time ever again. There is wiggle room in this. If I’ve proposed to observe galaxy clusters A, B, and C, and I realize the also observable cluster E fits my science goals better, on many scopes it’s okay if I add in E and maybe drop C. But, if I’m supposed to be studying the evolution of galaxy clusters, I probably shouldn’t be pointed at my favorite nebula all night.

The “generally requires” and “probably shouldn’t” in the above paragraph are there because there are certain times when I can point the telescope anywhere that I can safely observe without concern for the science I’m obtaining. Those times include mediocre weather (which prevents me from doing my science) and the fragments of the night when it’s dark enough to see a bright binocular object but not dark enough to see my beloved very faint objects (thus preventing me from doing my science).

The image of the Crab Nebula in the Subaru Press Release was taken in one of these stolen moments when some observations are possible, just not the desired observations of science targets. The press release doesn’t state what was wrong, but the normal culprits are clouds sitting only on top of the target object(s), winds coming out of the direction of the target object (at certain wind speeds, it isn’t safe to point the dome into the wind because the dome opening acts like a sail and tears the dome off its tack), or high cirrus is present blocking just enough photons to make faint object imaging impossible. While these three problems can destroy a science program (and make a grad student trying to finish a dissertation project cry), they do allow observers the freedom to take pretty pictures or target pet objects.

These images we steal with our multi-million (or even billion) dollar telescopes aren’t wasted photons. These images are often used for educational work, or to add data points to projects. For instance, according to Toru Yamanda, “My foreign colleagues are interested in the data, which could be useful for research into how the Crab Nebula expands over time.” If you look at a series of images taken over years, you can see the nebula slowly expanding, its tendrils of gas seemingly reaching out and engulfing more and more stars across the decades. As the Crab’s arms collide with material they may change shape and speed. With each new year’s images, we have a chance to see new changes in expansion rate and shape – Subaru’s image can be used to look for these changes. My own stolen moments at the telescope control console have been used to get pictures of large galaxies, star clusters and nebula that I now use to teach CCD data reduction and analysis to students.

But, at the end of the night, we all have to admit, we each like the occasional (and we really do hope they are occasional and brief!) moment we have to just look at something breathtakingly beautiful. Astronomy isn’t all about pretty pictures. The science images I need of star fields are in fact remarkably boring. But… While I am captivated by Astronomy’s deep intellectual mysteries, it was Astronomy s beauty the first seduced me, and that beaty still calls to me.

As we peer at stars in more wavelengths and in greater detail, we are beginning to find evidence of planetary systems around more and more objects.* As we witness this co-formation of stars and planets it is becoming impossible to stick stars in discrete boxes – Stars and planetary systems must be studied as a whole. This was brought home to me by a newly released Spitzer Space Telescope image of Helix nebula (above right, credit:NASA/JPL-Caltech/K. Su (Univ. of Ariz.)). This favorite object of amateur astronomers appears as a faint swirl of light through the eyepiece of a backyard telescope in a dark location. With Spitzer, it is resolved into concentric rings marking the location of a dead star. Around that dead star are the remnants of a cometary cloud.

At some point in the not too cosmologically distant past, a star not to different from our own Sun shut off. For billions of years, that star had first burned hydrogen to helium, and then helium into carbon. As it reached the end of its life, its atmosphere began to drift away and its light appeared to vary, until one day, the burning stopped. The helium fuel ran out, and with it the stars ability to keep burning ran out. What was left of the star’s outer atmosphere drifted away, and a carbon core was left behind. Today we see that carbon core as a white dwarf and that lost atmosphere the Helix planetary nebula. In this text book description of stellar evolution, however, we don’t see any discussion of what happened to any planetary objects that might have orbited the star.

In the Spitzer image we see a diffuse glow (appearing red in the above image) that comes from a dust disk extending from 35 AU to 150 AU from the central white dwarf. In our own solar system, this would place the inner edge of the disk slightly beyond Neptune and the outer edge well within the 526 AU orbit of the trans-Neptunian object Sedna. In our own solar system, the Kuiper Belt and a disk of scattered icy objects can be found in the same region we now observe a disk within the Helix nebula.

In a paper on this system, Dr. Kate Su (University of Arizona) and her team reason that the disk is generated by the collisions of comets. When the star that became the Helix nebula was young and stable it was surrounded by comets that were in stable orbits (and there could have been planets too – we just don’t have any evidence to say yes or no). When the star died, the comets’ orbits were disrupted, and now they are colliding in much the same way that comets (and everything else) in a still forming system collide. In a new born system, collisions between small objects can build big objects, and in the dieing system, collisions between big objects destroy big objects. From dust to dust.

This isn’t the first time a cometary disk has been found around a white dwarf. Last year a much smaller disk was found around G29-38. What makes this discovery so powerful is it is an object that is familiar, and that I can go outside and point to. I can say to my students – See that object? It used to be just like the Sun. It was surrounded by objects similar to things we have in our own solar system. We are watching it die. In 10,000 years that nebula will have drifted away. The comets are going to continue to destroy each other for a while, and the white dwarf in the center is going to slowly cool off and fade away for millions of years. Eventually, when man’s distant prodgeny look at that place in the sky it will be dark. And someday, when some entity looks at our solar system, it too will be dark. Everything is transitory, and when we look at the Helix, we see our future.

*Specifically, the Spitzer Space Telescope has allowed scientists to find asteroids belts around numerous nearby stars, to identify mega-planet forming disks around hypergiant stars, and finally start to directly measure such fundamental qualities as the day and night time temperatures on Jupiter-like planets circling sun-like stars.