天文觀測作業 HW020917

due in 2 weeks

1. What is the approximate angular separation (in seconds of arc) between a human's eyes seen at the distance of the moon? 

2. What are the best months to observe the constellation Taurus (RA~4 ^h in terms of its sky position?

3. The probability that an electron is at a distance r from the center of the nucleus of a hydrogen atom is given by
              P(r)=Cr²e^-2r/R
   Find the mean radius <r> and its standard deviation.

4. A graduate student (while the professor is asleep) measures the flux of a standard star (i.e. not known to vary its light) and record the following photometer readings in millivolts: 44, 48, 44, 38, 46, 45, 45, 47, 58, 43.   The measurement of 58 appears anomalously large compared to other values but our hardworking student is confident that it is not a mistake.  Should the student accept 58 as a legitimate record?  (Hint: Find out what the Chauvenet's criterion is.)

5. A star with an apparent magnitude of 8.5 has been resolved into a binary, with a flux ratio of 3.  What is the apparent magnitude for each of the component star? If this binary system is at a distance of 20 pc from earth, what is the absolute magnitude of the brighter star in the system?  Give a qualitative discussion for the situation if there is interstellar matter that absorbs the light from the star, how does this affect your result?