1. Phys 1810 Lecture 11: Office hours Allen 514
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Office hours Allen 514
Monday (today) between 3-4pm
This Class
Telescopes
Overview of planets
READ BEFORE COMING TO CLASS
Solar System Chapt 6
formation of the moon 8.8
exoplanets Chapt 15
Topics include
scale, objects
terrestrial vs jovian
planetary system formation including (differentiation)
Mars
Earth – climate change
planetary system formation including differentiation
ALL NOTES COPYRIGHT JAYANNE ENGLISH
Does everyone have the password?

2. Hubble Deep Field Light Gathering Power
2. Diffraction-limited Resolution
3. “Seeing”

3. 3. Seeing

4. Mountaintop Sites build high to get above most of the atmosphere
summary
Recall column
build high to get above most of the atmosphere

5. Highlights of Previous Class:
summary
Recall column
- Resolution is effected by atmospheric seeing. - Atmospheric transmission filters electromagnetic radiation.
Seeing is less affected at longer wavelengths. Near IR ground-based observations can be as high resolution as optical observations on the HST.
The atmosphere filters electromagnetic radiation to us ground based folk

6. Can observe at wavelengths that the Earth’s atmosphere blocks.
Above the atmosphere
far infrared view quite different
Optical
Far Infrared
Can observe at wavelengths that the Earth’s atmosphere blocks.

7. Which wavelength range(s) do you plan to observe at? Why?
Review:
Imagine that you and your neighbours are part of an international consortium planning to build a telescope to study very powerful, energetic supernova explosions. Discuss the following details of your plans:
Which wavelength range(s) do you plan to observe at? Why?
Will it be a space-based or ground-based observatory? Why?
Will these choices give you high or low resolution? Why?
Results of discussion (which is a synthesis of the material recently covered):
the wavelength regime for objects with a lot of energy: Gamma-ray, X-ray, UV.
Multi-wavelength observations are good too since Gamma-rays and X-rays are absorbed by dust that might be in between the earth and the SN. Supernova remnants (SNR) are discovered at radio wavelengths for example.
space-based telescopes are necessary for the high energy wavelengths like gamma-ray and x-ray since they are affected by the atmosphere being opaque for those wavelengths. Space-based is good for optical observations due to seeing.
ground-based for the radio telescopes since seeing doesn’t affect the longer wavelengths of IR and beyond.
it is also good to go to high energy regime since the resolution is higher with shorter wavelength.
(Note – there is no one right answer, as one can see from the multi-wavelength discussion.)

8. Afternoon class, see Lecture 9 for Doppler Shift

9. Planets in Our Solar System.
Now we have fundamentals:
Major force: gravity  motion
EM radiation: how it tells us about matter (elements, particles) and energy (temperature, magnetic fields) and forces (gravity)
Detect radiation: telescopes and instruments
 COSMIC TOPICS

10. Solar System Overview: Planet Definitions
Classical Planet
Orbits sun.
Massive enough that its own gravity has caused its shape to be nearly spherical.
It’s “cleared the neighbourhood” around its orbit of other bodies.
either by
colliding with (sweeping up) the debris, or
gravitationally kicking the debris out of its path (slingshot effect).
This leaves us with 8 planets.

11. Solar System Overview: Planet Definitions
Dwarf Planet
Orbits the sun.
Massive enough that is own gravity has caused its shape to be spherical.
Is not a satellite of another body.
(Has not cleared its neighbourhood.)
Exact wording is at . See International Astronomical Union Resolution 5A.
Examples:
Pluto
Eris (1.3 * Pluto’s mass)
Ceres (in the asteroid belt)
Objects at Neptune and beyond are called Trans-Neptune Objects (TNO) and those TNO that are similar to Pluto are called plutoids.

12. revolve & rotate in the same direction as other planets?
Solar System Overview: What does the class already know about the classical planets?
For each planet:
revolve & rotate in the same direction as other planets?
primarily composed of rock or of gas? # Earth Masses, # Earth radii
small or large? (i.e. closer to Earth size or Jupiter size?)
in outer region or inner region of solar system?
hot or cold? surface T in Kelvin
Lots of moons?
Any other details are welcome  (eg. Does it have rings? B field?)
If a planet spins in the same direction as its orbit, its spin is called “prograde”. If a planet spins in the opposite direction to its orbital motion, that spin is called “retrograde”.
See contributed notes from planet teams and do your own research to supplement these powerpoint presentations.

13. Solar System Overview:
Add to this table
Temperature & Magnetic field.
(Not kg, km but Earth mass and radii)
How do we know these things? we’ll do that after we talk about the classical planets so we don’t run out of time for our competition.
The first 8 are planets.
Note the second column.

14. Keplerian Rotation Curve.
Solar System Overview
Keplerian Rotation Curve.

15. Solar System Overview The density in kg/m
If the density of an object is less than that of water, then it will float.
The density in kg/m
1000 for water; if less than this, floats in water.
for rocks; for iron
Note 2nd last column & density of Earth.
Ask yourself which planets have densities like rocks/iron? Float on water? 3

16. How do we know these characteristics?
Check the notes that you wrote in class for deriving:
distance
diameter or orbital radius
mass
density
Wrote notes on overhead in class.