General Astronomy -
Spring 2013
Homework #2 - due February 4
Name __________________________
1. (2 pt) The European Hipparcos satellite made the best
stellar parallax measurements to date and could reach an accuracy of
about 1 milliarcsecond. How distant is the farthest star for
which Hipparcos could measure a distance?
2. (2 pt) Measure and record the distance from your eye to
your thumb with your arm extended and the width of your thumb.
Calculate the angular size of your thumb as seen from your eye with
your arm extended.
3. (1 pt) In terms of flux, how much dimmer is a 6th magnitude star
compared with a 1st magnitude star?
4. (2 pt) In terms of flux, how much dimmer is a star with absolute
magnitude = 6 compared with a star with absolute
magnitude = 1 that is 10 times farther away?
The following questions refer to the Mythbusters "Diet Coke and
Mentos" episode (season 4, volume 5 on DVD or collection 2, episode
7 on Netflix). This will be shown in class on February 1.
5. (1 pt) What is the first hypothesis that Jamie makes (and tests)
about the Diet Coke and Mentos phenomenon? Is their hypothesis
a legitimate scientific hypothesis?
6. (1 pt) Progress in science is often made by falsifying
hypotheses. Write down a hypothesis involving one chemical
component of Diet Coke that Adam falsifies.
7. (1 pt) Are there any flaws in the "proof" that nucleation on the
Mentos surface is important? What would be a better test?