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Unformatted text preview: ass of the part of the Milky Way within the Sun’s orbit in solar masses.
HINT: Use the results of the last problem. You may need to do several unit
conversions here, clearly state your reasoning for full credit.
6. [C&O 3.3 (tweaked)] The parallax angle for Sirius is 0.379".
a. Find the distance to Sirius in units of (i) parsecs; (ii) light-years; (iii) AU.
b. Estimate the flight time of the fastest spacecraft we have, New Horizons,
to Sirius (if it was headed that way). It will take New Horizons 9 1/2 years
to cover the distance between the Earth and Pluto (~32 AU).
c. Determine the distance modulus for Sirius. Does the result make sense?
NOTE: Problems 6 to 8 are variations of problems originally in Sparke and Gallagher’s
Galaxies in the Universe (2nd Edition).
7. To determine a star’s trigonometric parallax, we actually need at least three
(preferably more) measurements of its position relative to much more distant
objects during the course of a year: why? HINT: What...
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This document was uploaded on 03/04/2014 for the course ASTROPHYS 362 at Minnesota State University Moorhead .
- Spring '14