The Disk Revealed
My first two posts about the Seattle AAS meeting focused on the two Citizen Sky posters and a slew of posters and the special session dedicated to epsilon Aurigae. This post is fulfillment of a promise: a discussion of the interferometry poster, along with one extra bonus: a "wow" image.
If you are new to the project (welcome ~300 students from Tufts), a team of 17 astronomers have been observing the eclipse of epsilon Aurigae using the Michigan InfraRed Combiner (MIRC) with Georgia State University's Center for High Angular Resolution Astronomy (CHARA) interferometer. CHARA is an array of six 1-meter telescopes spaced a maximum of 331 meters apart. When the light is combined (using MIRC) the whole system acts as if it were a single-mirror telescope with a diameter of 331 meters. This results in a resolution of 0.5 milliarcseconds in H-band.
On behalf of 16 coauthors, I presented a poster entitled "Interferometric Images of the Transiting Disk in the Epsilon Aurigae System" at the Seattle AAS meeting which detailed eight epochs of observations, images from two different image reconstruction methods (interferometers don't take images like a traditional telescope), initial model fits to the data, and a discussion of the artifacts we see in the images.
My favorite part of the poster comes in the form of a single image:
This figure shows images from all eight observations positioned according to an initial orbital fit for the system (with a little tweaking) and blended together to reveal the eclipsing object as it has never been seen before. (Sorry about the text in the image, but I've had some trouble lately with people using images and not citing their source).
Now that the eclipse is almost over the CHARA team is now tasked with final model fitting to the data and writing up the results for the currently obtained epochs. We also have one more opportunity to observe eps Aur with CHARA when their observing season opens in April, but with the star setting quickly and the egress phase only lasting 60 days it'll be a difficult observing program. Stay tuned for more details.