The first talk of the day Wednesday at the 220th meeting of the American Astronomical Society centered on observing, and not just modeling, the insides of stars like our Sun. // photo by NASA/SDO
Another interesting and universe-filled Wednesday unfolded in Anchorage, Alaska, the third (and final) full day of the 220th meeting of the American Astronomical Society (AAS). Instead of an overarching theme uniting most of the talks, today I saw a hodge-podge of lectures and sessions covering many of astronomy’s diverse disciplines.
The day began with a metaphorical sunrise (the best we can do in overcast and never-dark Anchorage) when Yvonne Elsworth of the University of Birmingham in England discussed, “How to Observe (Rather Than Model) The Interior of Stars.” So, how to do this? “The Sun resonates like a (three-dimensional) musical instrument,” Elsworth explained, allowing scientists to use seismological techniques to probe and analyze our star. “Seismology genuinely gets under the Sun’s skin.” Armed with the “wonderful, wonderful Kepler data” now available, astrophysicists can study populations of stars in unprecedented detail. For fans of stars, and especially the Sun, Elsworth concluded these are “very exciting times.”
Next up was a press conference that included some familiar subjects: “Exoplanets & Brown Dwarfs.” One of the speakers, Thomas G. Beatty of the Ohio State University in Columbus detailed once more the discoveries from the Kilodegree Extremely Little Telescope (KELT), which he called “small but fierce.” Good for him! Another presenter, Tristan Guillot of the Côte d’Azur Observatory in France, spoke about “The Brown Dwarf Desert: A Tale of Stars Engulfing Their Companions.” For certain stars, astronomers had expected to find close-orbiting brown dwarf companions, but Guillot explained that tidal forces between the dwarf and the star would likely tug on the brown dwarf, sending it crashing to its doom with the star. It’s research that will help astronomers understand not just these specific systems, but also the ultimate fate of our home planet (which might eventually be swallowed up by our own host star).
Lars Buchhave of the University of Copenhagen announced that Earth-like planets can form around many more stars than previously thought, implying that our galaxy might be teeming with terrestrial worlds. // photo by Bill Andrews
The biggest news at the conference, though, probably came from Lars Buchhave of the University of Copenhagen in Denmark. He joked that his talk’s title, “Small Planets Do Not Require A Metal-Rich Environment,” was probably “giving away the punch line." The finding has implications for the number and age of the galaxy’s Earth-like planets. Gas giants are most often found around “metal-rich” stars, meaning one with elements more complex than hydrogen and helium. But smaller, terrestrial planets turn out to form just as easily around metal-rich stars as around metal-poor stars. “Thus, small planets might be widespread in our galaxy,” Bucchave said — and because metal-poor stars have been around longer, terrestrial planets might have formed much earlier than previously thought possible. His research is published online today
The last talk before lunch was, “Bubble, Bubble, Toil, And Trouble: A Theorist’s Romp Through The Cosmic Dawn,” by Steven R. Furlanetto of the University of California, Los Angeles. No witches appeared, but Furlanetto did include a quote from Shakespeare on each of his slides, in exchange for altering a quote in his title. (The actual line from Macbeth is “Double, double toil and trouble.”) In addition to enlightening us with Shakespeare, Furlanetto worked to explain the significance of the cosmic dawn, that time when the universe was just starting to form the structures that would lead to galaxies and stars. He also discussed the current methods scientists use to study that time and their considerable drawbacks. Luckily, we’re entering an age where astronomers’ tools are powerful enough to make significant progress (including the latest Ultra Deep Field from Hubble, due out later this summer). “Observations are going to be really key,” he said, “and we’re starting to get them.”
Australian physicist and radio astronomy pioneer Ruby Payne-Scott proved instrumental for both the science of astronomy and the role of women within it. // photo by Peter Gavin Hall
Things got a little personal after lunch, in a good way, with a talk from W. Miller Goss of the National Radio Astronomy Observatory in Socorro, New Mexico, entitled, “Under the Radar: The First Woman in Radio Astronomy, Ruby Payne-Scott.” Taking advantage of what would have been Payne-Scott’s 100th birthday two weeks ago (May 28), Goss gave a short biographical sketch of the remarkable woman, one of the first to earn a bachelor’s degree in physics in Australia. Her gender limited her scientific prospects until World War II broke out, when “all of a sudden there were jobs opening up for women.” She smoothly transitioned from radar work during the war to a pioneering career in science; she was one of the first people ever to do radio astronomy, and (as the title states) the first woman. Sadly, despite achievements that helped establish a whole discipline within astronomy, the final episode of her scientific career was having to resign because she got pregnant — she had only spent six years as a radio astronomer. Still, her public complaints helped pave the way for future women to achieve a greater sense of equality in science. Pretty good for an Australian girl who never even learned to drive!
Immediately following this lecture, familiar face Brian P. Schmidt of the Australian National University in Canberra moved things back into space — but kept them Australian — with the day’s final talk, “SkyMapper: Surveying the Southern Sky.” Schmidt said, “You can think of it as analogous to the Sloan Digital Sky Survey,” only instead of focusing on galaxies, it’s optimized for stellar astrophysics. Despite some pretty serious technical discussions of the 1.35-meter scope, the CCD, and observatory facility, Schmidt kept the talk fun with his casual comparisons and a penchant for anecdotes. (At one point, he made an offhand comment about having to “deal with the Russian mob,” and kept us hanging till the very end of the talk, when he described the shady Russian company that delivered a $40,000 instrument in a pizza box, complete with cheese and grease-stained paper.) The project will be able to search out metal-poor stars, hypervelocity stars, quasars, and much more. “There’s a lot of things to do,” Schmidt said excitedly, and he invited everyone to “please come and work with us!” It almost made we want to be an astronomer.
All the junk in orbit around our planet, whether from discarded rocket parts, unintended collisions, or just chipped off paint flecks, poses an ever-increasing problem. // photo by NASA/JSC
The day’s final event, and a main highlight of the trip, was a screening of the IMAX movie Space Junk 3D.
I’d thought, what with the science-iness and the IMAX-ness of it, that we’d be going to a planetarium or science museum — nope! The Regal Tikahtnu Stadium 16, right here in Anchorage, was our destination, and as soon as I walked in the place, familiar popcorn smells hit me. Some of the other AAS attendees (it took three chartered buses to transport us all there) actually got some food for themselves, but I’d just eaten. The movie itself was pretty good, for an approximately 40-minute documentary. It focused, as one might expect, on the dangers space junk pose to existing satellites, the International Space Station, and our space-dependent society. (Don’t think we are? Consider how every tweet, text message, Facebook post, and GPS system work.) In particular, the film discussed the “Kessler Effect,” named for NASA scientist Don Kessler, who explained within the movie how each collision in orbit unleashes more bits of space junk, making future collisions (and even more junk) that much likelier. The 3-D effects weren’t just a gimmick, as they so often are nowadays, and all of the models and simulations in space really came to life: the crash of satellites Kosmos-2251 and Iridium 33
, for example, happened right before our eyes and helped drive home the importance of developing methods to help clean up the skies. It was a great showing, and if you’ve ever had an astroimage marred by a satellite trail, or just care about our spacefaring future, you’d probably enjoy it.
And there we have it! It’s hard to believe the main three days of the AAS summer conference are already over. Normally, I’d be heading back home about now, but because Alaska’s such a hard place to get to, we figured I might as well stick around and go to some of the talks on Thursday, tomorrow. I do have to leave before the final events, sadly, but I’ll be sure to write up everything I see in my next (and final) blog post, and live tweet throughout the day (#AAS220).