The Solar System and Exoplanets Flashcards
1
Q
What is the solar system made of
A
- 4 Rocky Planets
- Asteroid Belt
- 4 Giant Planets
- Kuiper Belt
- Oort Cloud
2
Q
What is the equation for
Planetary Temperature
A
- Assume planet is a black body
- Assume Thermal equilbrium
- Flux = Luminosity
- T = (L/16πσd^2)^1/4
T = Temperature, L = Luminosity of heat source (sun), σ = stephan const
3
Q
What are the
Methods of Exoplanet Discovery
A
- Radial Velocity Method
- Transit Method
- Microlensing
- Astrometry
- Direct Imaging
4
Q
Describe the
Radial Velocity Method
A
- Works for Jupiter Like planets orbiting solar type stars
- Using the centre of mass (treating it like a binary star system), radius of star’s orbit can be found
- Using orbit radius and period, velocity can be found
- Using doppler effect, such motion can be used to detect exoplanets
5
Q
Describe the
Transit Method
A
- When orbital plane of exoplanet lies edge on (i=90)
- Exoplanet will transit, periodically decreasing apparent flux observed from Earth, as exoplanet covers part of the stellar disk
6
Q
What is the equation for
Transit Depth
A
δ =(Rp/Rs)^2
δ = transit depth, Rp = radius of exoplanet, Rs = radius of sun
7
Q
What is the equation for
Transit Duration
A
D = (P/π)sin-1(Rp+Rs)/a
D = duration, P =orbital period, a = orbital radius
8
Q
What is
Microlensing
A
- Same principle as Gravitational lensing
- The planet will cause further gravitational lensing of background light
- Allows us to detect exoplanets at around 1-2AU
9
Q
What is
Astrometry
A
- Solar type stars will orbit Jupiter like planets
- Measuring the position of the star in the sky, we can detect this motion
- This will detect Jupiter like planets
10
Q
What is
Direct Imaging
A
- Planets emit little light and have small angular separations from stars
- Young exoplanets retain heat from formation
- Young exoplanets are brighter, easier to detect
