Please staple 1+2 and 3+4.
1. Planet Around HD 63454
HD 63454 is a 0:7M star known
to have an extrasolar planet
orbit-ing it in a circular orbit with
an or-bital period of 2.82 days.
The dis-tance to this system is
35.8 pc and the measured radial
1. Distances to Sun and Moon
In this course we are mostly concerned with post-Newtonian astronomy. But it would be
unfair to ancient astronomers to ignore them completely, since they managed to gure
out quite a lot about our Solar system. Greek astronomy
PHY 4201 Final Exam Review
1) The pp chain is predominantly going through 3 steps:
d + p !3 He +
He + He ! He + 2p
a) What is the characteristic temperature required for the complete pp chain to
ignite under typical conditions of a s
Problem set 2
(1) Write down Friedmanns equation for the scale factor of the universe, R(t). Assuming
that the universe contains pressureless matter only, so that (t) = 0 (R/R0 )3 , rewrite the
equation in terms of the variable , w
PHY 4201 Sample Quiz
Problem 1: In Radio Astronomy, arrays of many individual radio telescopes are used to improve
the spatial resolution of the radio observations.
a) Explain the principles of aperture synthesis! What is the minimum number of radio teles
I. Law of Inertia
Newton's first law is basically a statement of conservation of linear momentum, p = mv.
The law states:
"The velocity of a body remains constant unless the body is acted on by an outside
"A body at rest
We are now going to study orbits in some detail, but first we need to review some basic
mechanics such as you learned in your Freshman Physics class. In particular, we need
motion (coordinates, vectors, velocity, acceleration
PHY 4201 Sample Quiz
Problem 1: At what wavelength will the following spectral lines be observed:
a) A line emitted at 500 nm by a star moving toward us at 100 km/s. (4 points)
b) The Ca II line (undisplaced wavelength of 397.00 nm) emitted by a galaxy re
Telescopes and Detectors
Lenses, Mirrors and Optics
Telescopes come in two basic types: refracting telescopes (using a lens as its main
element: 1, 2, 3 ) and reflecting telescopes (using a mirror as its main element: 1, 2, 3).
Simple ray tracing techniqu
A. What Is a Star and Where Do They Come From?
You may wonder how we decide between various objects such as stars and planets.
Here are some possible statements that may seem reasonable to distinguish them:
Planets orbit around stars (wrong! [movie])
A. Our Solar System
Obviously as scientists began thinking about how planetary systems are formed they
began by considering the only example we had before 1995-our own solar system.
When we look at our solar system in the "modern" sense as defined by Cope
A. Interstellar Medium (ISM)
Solar wind and IPM (Interplanetary Medium)
carries particles and magnetic fields outward
defines the Heliosphere (region of space dominated by the Sun)
each star has a similar region of domination around it
Physical Interpretation of Kepler's Laws
Kepler's first law states that the planets move in elliptical orbits around the Sun, with the
Sun at one focus. Elliptical orbits are indeed a property of inverse square law central
forces, as we will show shortly.
1. Extended Source
Consider a roughly circular extended celestial source with an angular radius = 30 .
(a) Calculate the solid angle subtended by this source.
(b) If the intensity I is uniform over the source, calculate the specific flux measured by a