20/06/2022, 01:57 Week 1
Week 1
Units in Astronomy
Observing the sky
Zenith is the point directly above Celestial Sphere
Star Circles at different latitudes In Melbourne, our latitude is 38º South. That
means that the Pole is 38º above the horizon.
https://paper.dropbox.com/doc/print/HgltFIo0ftdRLKCKyupxo?print=true 1/2
,20/06/2022, 01:57 Week 1
The celestial equator is tilted by 23.5° to the ecliptic.
https://paper.dropbox.com/doc/print/HgltFIo0ftdRLKCKyupxo?print=true 2/2
, 20/06/2022, 01:59 Week 2
Week 2
Lecture 1
Planetary Orbits
Eccentricity = distance between foci/semi-major axis If eccentricity = 0 it is a
perfect circle
Kepler’s Laws of Planetary Motion
Planetary orbits are ellipses with the Sun at one focus
In equal intervals, a planet’s orbit sweeps out equal areas
The relationship between the orbital period (P) and the semi-major axis (a) of
an orbit is given by P 2 = a3 (when a is in units of AU and P is in units of Earth
years).
Newton’s Laws of Motion
Objects continue to be at rest or move with a constant velocity unless acted
upon by an outside force
https://paper.dropbox.com/doc/print/HRYkS88MdVcm3FcO4iHYQ?print=true 1/4
Week 1
Units in Astronomy
Observing the sky
Zenith is the point directly above Celestial Sphere
Star Circles at different latitudes In Melbourne, our latitude is 38º South. That
means that the Pole is 38º above the horizon.
https://paper.dropbox.com/doc/print/HgltFIo0ftdRLKCKyupxo?print=true 1/2
,20/06/2022, 01:57 Week 1
The celestial equator is tilted by 23.5° to the ecliptic.
https://paper.dropbox.com/doc/print/HgltFIo0ftdRLKCKyupxo?print=true 2/2
, 20/06/2022, 01:59 Week 2
Week 2
Lecture 1
Planetary Orbits
Eccentricity = distance between foci/semi-major axis If eccentricity = 0 it is a
perfect circle
Kepler’s Laws of Planetary Motion
Planetary orbits are ellipses with the Sun at one focus
In equal intervals, a planet’s orbit sweeps out equal areas
The relationship between the orbital period (P) and the semi-major axis (a) of
an orbit is given by P 2 = a3 (when a is in units of AU and P is in units of Earth
years).
Newton’s Laws of Motion
Objects continue to be at rest or move with a constant velocity unless acted
upon by an outside force
https://paper.dropbox.com/doc/print/HRYkS88MdVcm3FcO4iHYQ?print=true 1/4
