Loose Leaf For Explorations: Introduction To Astronomy
9th Edition
ISBN: 9781260432145
Author: Thomas T Arny, Stephen E Schneider Professor
Publisher: McGraw-Hill Education
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Chapter 14, Problem 9TY
To determine
Reason for stars doesn't form the iron core during their evolution.
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For a main sequence star with luminosity L, how many kilograms of hydrogen is being converted into helium per second? Use the formula that you derive to estimate the mass of hydrogen atoms that are converted into helium in the interior of the sun (LSun = 3.9 x 1026 W).
(Note: the mass of a hydrogen atom is 1 mproton and the mass of a helium atom is 3.97 mproton. You need four hydrogen nuclei to form one helium nucleus.)
QUESTION 16
Use the figure shown below to complete the following statement: A low-mass protostar (0.5 to 8M the mass compared to our sun) remains roughly constant in
decreases in
until it makes a turn towards the main sequence, as it follows its evolutionary track.
Protostars of different masses follow diferent
paths on their way to the main sequence.
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type
0.01 R
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60 M
MAIN SEQUENCE
40,000 30,000
20 Mau
10 Mgun
5 Mun
0.1 Run
Ren
radius; temperature
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temperature; luminosity
Oluminosity: temperature
radius: luminosity
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Absolute visual magnitude
and
Betelgeuse is a nearby supergiant that will eventually explode into a supernova. Let's see
how awesome it would look. At peak brightness, the supernova will have a luminosity of
about 10 billion times the Sun. It is 600 light-years away. All stellar brightnesses are
compared with Vega, which has an intrinsic luminosity of about 60 times the Sun, a distance
of 25 light-years, an absolute magnitude of 0.6 and an apparent magnitude of 0 (by
definition).
a) At peak brightness, how many times brighter will Betelgeuse be than Vega?
b) Approximately what apparent magnitude does this correspond to?
c) The Sun is about -26.5 apparent magnitude. What fraction of the Sun's brightness will
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Chapter 14 Solutions
Loose Leaf For Explorations: Introduction To Astronomy
Ch. 14 - Prob. 1QFRCh. 14 - Prob. 2QFRCh. 14 - Prob. 3QFRCh. 14 - Prob. 4QFRCh. 14 - Prob. 5QFRCh. 14 - Prob. 6QFRCh. 14 - Prob. 7QFRCh. 14 - Prob. 8QFRCh. 14 - Prob. 9QFRCh. 14 - Prob. 10QFR
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