Physics 134 Homework Set 7 Solutions
1. The star Aldebaran, in Taurus, has a surface temperature of 3934 K. (a) What is Aldebaran's wavelength of maximum emission? What color would you expect it to be
Physics 134 Homework Set 6 Due 2/20/13
1. Let's try to find the Roche limit, the distance from a planet at which a moon would be broken apart by tidal forces. We will make a few simplifying assumption
Physics 134 Homework Set 1 Solutions
1. Here are some applications of the small-angle formula. It is actually a useful tool to carry around, astronomy aside. (a) The Duke Chapel tower stands 210 ft. t
Physics 134 Homework Set 10 Solutions
1. Assume that the Sun formed 4.5 billion years ago with an essentially uniform composition (in the early Sun convection destroyed chemical differentiation). The
Physics 134 Homework Set 11 Due 4/10/13
1. Kapteyn's star has a parallax angle of 0.255 arcseconds. (a) What is the distance to Kepteyn's star in pc? Distance and parallax angle are related by 206265"
Physics 134 Homework Set 12 Due 4/17/13
1. The star Cephei varies in brightness with a period of 5.4 days. Its spectrum contains plenty of heavy element lines, showing it is a Population I Cepheid var
Physics 134 Homework Set 2 Solutions
1. Describe how you would go about finding the star Mirfak which lies in the constelation Perseus at Decl. 49 52m ; R.A. 3h 24m in the sky in Durham on February 3
Physics 134 Homework Set 3 Solutions
1. (a) About how many more sidereal days are there in a year than solar days (tropical or sidereal year is immaterial here)? At the level of accuracy expected here
Physics 134 Homework Set 4 Solutions Due 2/6/12
1. We observe that oppositions of Saturn repeat every 378 days. (a) Use this information to find the sidereal period of Saturn, in (Earth) years. You ma
Physics 134 Homework Set 5 Solutions
1. In the last HW you computed Saturn's radius. Let's follow that calculation up to see what else we can learn using what we now know. (a) Saturn's moon Janus orb
Physics 134
Homework Set 4
Due 9/22/17
1. Comets orbit the Sun, as we mentioned, in highly elliptical orbits. Lets see how
elliptical, using Keplers laws.
(a) Halleys comet orbits with a sidereal peri
Physics 134
Homework Set 2 Solutions
1. Describe how you would go about finding the star Mirfak which lies in the constelation Perseus at Decl. 49 52m ; R.A. 3h 24m in the sky in Durham on February 3
Physics 134
Homework Set 3 Solutions
1.
(a) About how many more sidereal days are there in a year than solar days (tropical
or sidereal year is immaterial here)?
At the level of accuracy expected here
Physics 134
Homework Set 5 Solutions
1. Lets try to find the Roche limit, the distance from a planet at which a moon would
be broken apart by tidal forces. We will make a few simplifying assumptions a
Physics 134
Homework Set 14 Solutions
1. The density of normal (baryonic) matter in the Solar neighborhood is about 0.054M /pc3 .
What is this in kg/m3 ? Assuming this is entirely in the form of Hydro
Physics 134 Homework Set 8 Solutions
1. In class, we computed the surface temperature of Earth, assuming it was in equilibrium with Solar radiation and noting the importance of the atmospheric greenho
Physics 134 Homework Set 9 Solutions
1. We estimated the temperature at which a cloud becomes unstable to gravitational collapse to be given by kB T
GM m R0
where M is the total mass of the cloud, R0
Physics 55 Final Exam 4/30/12
General Instructions The rules are the same ones that have applied to all of our exams. You may use your notes, the text, lecture slides, and any course material. You may
Physics 55 Midterm Exam 4/10/12
1. Centauri has a parallax angle of 0.75 arc-seconds. (a) [5pt] Find the distance to Centauri. Distance in pc is related to parallax angle by D = 1/p = (0.75)-1 = 1.33
Physics 55 Midterm Exam 4/10/12
1. Centauri has a parallax angle of 0.75 arc-seconds. (a) [5pt] Find the distance to Centauri. (b) [5pt] The apparent brightness of Centauri is approximately 2.07 10-11
Physics 55 Midterm Exam 2/27/12
Answer the following questions (4 pts each) 1. The star Castor in Gemini has celestial coordinates approximately R.A. = 7h 34m 36s , Decl. +31 53m 18s . Viewed from Dur
Physics 55 Midterm Exam Solutions 2/27/12
Answer the following questions (4 pts each) 1. The star Castor in Gemini has celestial coordinates approximately R.A. = 7h 34m 36s , Decl. +31 53m 18s . Viewe
Physics 134 Quiz 3 4/3/13
Briefly answer 3 of the following questions. 2-3 sentences should suffice where the answer is not a calculation.
1. The Cassini Division is the large gap between the A and B
Physics 134 Quiz 3 4/3/13
Briefly answer 3 of the following questions. 2-3 sentences should suffice where the answer is not a calculation.
1. The Cassini Division is the large gap between the A and B
Physics 134 Midterm Exam 3/7/13
In solving the exam problems you may use any material associated to the class. It is essential that you show your work: putting down some number with no explanation wil
Physics 134 Midterm Exam Solutions 3/7/13
In solving the exam problems you may use any material associated to the class. It is essential that you show your work: putting down some number with no expla
Physics 134 Quiz 1 Solutions 1/24/12
Imagine that the Earth suddenly reversed the direction in which it spins, rotating from East to West at the same rate at which it now spins West to East. Answer th
Physics 134 Quiz 1 1/24/12
Imagine that the Earth suddenly reversed the direction in which it spins, rotating from East to West at the same rate at which it now spins West to East. Answer the followin
Physics 134 Quiz 2 2/13/13
1. As we mentioned, there was a total lunar eclipse on Dec. 21, 2010. (a) About what time did the Moon rise on Dec. 21? (b) A partial Solar eclipse (visible in Europe and Af
Physics 134 Quiz 2 Solutions 2/13/13
1. As we mentioned, there was a total lunar eclipse on Dec. 21, 2010. (a) About what time did the Moon rise on Dec. 21? Lunar eclipses happen during full Moon, wh