Monday, June 7, 2010

Exoplanets Presentation to Temecula Valley Astronomers

I'm presenting my show on exoplanets to my astronomy club tonight. A map to our meeting place is available here: Temecula Valley Astronomers meeting place.

My show, as well as my understanding of the content, has evolved. I've posted an older version that I will be updating after I finish my presentation here: Exoplanets

Not yet included on my online version are illustrations such as the following:

Illustration: WASP-18b grazing it's star's surface.
Such an event is expected to occur in the next million years,
assuming current Tidal Dissipation Theory is correct.

Above is the closing sequence of illustrations explaining how the moon is moving outward due to tidal forces transferring angular momentum of Earth's spin to the moon's orbit.

The above effect can happen in reverse when the star is spinning more slowly
than the planet, like WASP-18b:

Above: The massive planet WASP-18b is orbiting at 0.02 AU and rotating faster than the star.
Here I've shown it pulling the tidal bulge of the star,
resulting in a loss of angular momentum and a closer orbit.

Tidal Dissipation Theory is based on observations of binary stars and of our solar system's gas giants. WASP-18b is a middle case between these and therefore a test of Tidal Dissipation Theory:

Astronomers project that within 10 years further observations of this system will show detectable change due to tidal dissipation. If such change is not observed, it will force a re-examination of Tidal Dissipation Theory.
As a lay observer, I see it plausible that tidal dissipation theory will be get revised. As pointed out by the review of the research (both review and paper printed in Nature 27 Aug. 2009), the chances of finding a planet with 1 million years left is 1 out of 1000; yet WASP-18b's discovery was 1 out of 320, a number in itself that's questionable given the newness of this area of research. I eagerly await the results, that is, whether 10 years reveals a decaying orbit.


Update: It looks like I'm on the activities list for the Julian Starfest on Aug. 7/8; I plan to show Exoplanets then, which gives me two months to enhance, embellish and take requests.

1 comment:

metapsyche said...

Very nice write up on Tidal Dissipation involving Exoplanets!
I tweeted about it on coz it was worth sharing!