PHYS-333-13s: Problem set #2
Version of February 23, 2013.
1. Visual binary (15 points):
Over a period of 10 years, two stars separated by an angle of 1 arcsec are observed to
move through a full circle about a point midway between them on the s
Phys333-13s HW7 Solutions
#1 Application of Tully-Fisher relation
z = 0.23;
Dl = 0.0013;
mI = + 17.6;
c = 3 10 ^ 5 km s ;
a. Orbital velocity Vrot
Vrot = c * Dl 2; H* Doppler width is from 2*Vrot,
so need to divide by factor 2 to get Vrot*L
PHYS-333: Fundamentals of Astrophysics
Department of Physics & Astronomy, University of Delaware, Newark, DE 19716
Version of October 26, 2013
I. STELLAR PROPERTIES
1 Observational vs. Physical Properties of Stars
2 Inferring Astr
Phys333-13s HW6 Solutions
#1 Stellar Collisions
#2 Galactic Orbital Periods
#3 Virial Mass of Cluster
#4 Galactic Rotation from 21 cm Radio observations
#5 Quasar properties from redshift
Welcome to Phys333-13S
Fundamentals of Astrophysics
Prof. Stan Owocki
205 Sharp Lab
The physical laws and forces that govern our lives.
e.g. gravity, ele
!Homework Reading Quiz!
What is orbital speed of earth around sun, in km/s?!
2 au/yr = 30 km/s = 10-4 c!
How many powers of ten between size scale of people
(1m) and that of the observable universe?!
Log[10 Gly/m] ~ 26!
What are 3 observab
Hydrogen energy levels
Light as Information Bearer
We can separate light into its different wavelengths (spectrum).
By studying the spectrum of an object, we can learn its:
PHYS-333: Problem set #1
VERSION of February 12, 2013 .
1. Energy ux and magnitude:
a. Suppose two objects have energy uxes of f and f + f , where f
f . Derive
an approximate expression for the magnitude dierence m between these two objects.
PHYS-333: Problem set #3
Due Classtime Mar. 7
Please write neatly and show your work. Answers correct to two decimal places
will receive full credit, so try to compute by hand without a calculator. Big magnitude
answers should be given in scientic notatio
Phys333-13s HW4 Solutions
#1 Opacity of people vs. electrons
a. Cross section of standing person
cm =.; h = 1.8 m; w = 0.5 m; m = 100 cm; s = h * w; NumberForm@s, 2D
b. Opacity for m=60 kg
m = 60 kg;
kg = 1000 g;
k = s m;
PHYS-333: Problem set #7
Due classtime Tuesday May 10
Please write neatly and show your work. Please put a box around all your final
answers. Answers without a box may not receive credit. Big magnitude answers
should be given in scientific notation. Answe