Thursday, April 18, 2013

Kepler Press Conference: 4/18/2013

Today at 2:00 PM, NASA is holding a press conference to announce the latest results from the Kepler Mission. I will be watching the press conference live and updating this post as we go. When the press conference is completed, I will provide a summary of the information.

2:00. Panel members are Paul Hertz, NASA's astrophysics director, Roger Hunter, Kepler project manmager, William Borucki, principal science investegator for Kepler, Thomas Barclay, Kepler scientist, and Lisa Kaltenegger, research group leader at the Max Planck Institute for Astronomy.

2:05. And we're live. Opening remarks from Dr. Simon Worden "This is really cool."

2:11. Roger Hunter: Introduction and motivation of the mission. Outlining basic mission goals and mission findings so far. Announces two planetary systems. One with two habitable zone planets that are larger than Earth. One with one planet solidly in the habitable zone and one on the edge of the habitable zone. Kepler 62e and Kepler 62f are 1.6 and 1.4 times the size of the Earth respectively. Images from the press conference shown below.

(Yeah, clearly I lifted these images directly from the video presentation, as you can tell from the "Press Esc to exit full screen mode" dialog that I didn't wait to clear when screencapping.)

Image courtesy NASA.
Proper version of this image. Credit NASA and Kepler Mission.
William Borucki: "We have not measured the masses of these planets."

Other system announced: Kepler 69. Planet Kepler 69c is on inner edge of habitable zone as shown below, and is 1.7 times the radius of the Earth.
Image credit: NASA and Kepler Mission.
Kepler 62 is smaller than our Sun, and Kepler 69 is roughly the size of our Sun, but a tad smaller.

Image Courtesy NASA
From Lisa Kaltenegger: Kepler 62e needs clouds to be properly habitable. Kepler 62f requires a thicker carbon dioxide atmosphere because it is farther out.

Of course, determining the mass of the planet is one of the critical points remaining. However, these planets are definitely too small to be detected with the radial velocity method, which is how we typically determine the mass of an extrasolar planet. This looks more like a situation in which transit timing variations will be helpful.

Transit timing variations are the small changes that occur in the exact orbital period of a planet based on other planets in the system pulling on one another through their own gravity. While these changes tend to be very small, Kepler is good enough to measure these, and it has apparently become the leading way in which the masses of Kepler planets have been confirmed (according to Dr. Eric Ford).

3:00 update: William Borucki addresses transit timing variations: the planets are not close enough to have significant gravitational influence on one another. Guess TTVs won't work after all. Damn.

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