An Eclipsing Extrasolar Planet

Extrasolar Planets!

- very dim - almost impossible to see (think floodlight vs. glow-in-the-dark watch)

Extrasolar Planets!

- very dim - almost impossible to see (think floodlight vs. glow-in-the-dark watch)

- easier to detect by looking at a star’s “wobble”

Center of Mass

Same mass; center of mass is in the middle.

Balance point is halfway between us.

Center of Mass

Center of mass (or, the balance point) is closer tothe more massive one.

Center of Mass

Center of mass (or, the balance point) is closer tothe more massive one.

Doppler Shift

Fire truck standing still Fire truck moving

The pitch of the moving truck's siren appears to change as it approaches and then passes us because the

waves get squished and then spread out.

Doppler Shift

Things moving toward usThings moving toward usare blue shifted.are blue shifted.

Things moving away from usThings moving away from usare red shifted.are red shifted.

Doppler Shift

Things moving toward usThings moving toward usare blue shifted.are blue shifted.

Things moving away from usThings moving away from usare red shifted.are red shifted.

Doppler Shift

Doppler Shift

- cops use it to tell how fast you're driving

Doppler Shift

- cops use it to tell how fast you're driving

- coaches use it to see how fast you're pitching

Doppler Shift

- astronomers use it to measure how much a star is wobbling!

Doppler Shift

- astronomers use it to measure how much a star is wobbling!

Doppler Shift

- watch out for inclination...

Inclination and Transits

- if we see a transit, we know it's close to edge-on

Starlight we can see:

1) 100% 2) ~99.5% 3) ~99.0%

p2 = a3

p is in years, a is in AU

__ days x 1 yr/365 days = __ yrs

(planet’s area) / (star’s area) = % light blocked

Just a little reminder...

100%99%