AST104 Module 2 Exam Questions and
Answers
What was the surprising finding of Cecilia Payne's 1925 doctoral thesis on the
elemental composition of star - ✅✅All stars are composed of mostly hydrogen
and some helium, with only traces of other elements.
What process is primarily responsible for powering the light emitted by most
stars? - ✅✅nuclear fusion of hydrogen into helium
The inward crushing force of the Sun's mass under its own gravity is balanced by
the outward explosive pressure from heat released by fusion in the core in an
example of - ✅✅equilibrium.
Where does the energy released by fusion of hydrogen into helium come from? -
✅✅The difference in mass of the hydrogen and helium is converted to energy
in the form of heat.
What was Annie Jump Cannon's insight into spectral classes? - ✅✅Spectral
classes should be ordered by temperature from hottest to coolest.
In searching for a planet very similar to Earth, which star is most similar to the Sun
and would therefor make the best candidate to study? - ✅✅61 Ursae Majoris
(class G8)
Order the following stars according to spectral class from hottest to coolest. -
✅✅1.
, Spica (B1)
2.
Sirius (A0)
3.
Polaris (F7)
4.
The Sun (G2)
5.
Capella (G3)
6.
Trappist-1 (M8
As astronomers use the term, the parallax of a star is - ✅✅one half of the angle
that a star shifts when see from opposite sides of the Earth's orbit.
Stars with larger parallax angle are __________ stars with smaller parallax angle. -
✅✅closer than
Why did it take astronomers until 1838 to measure the parallax of the stars? -
✅✅he stars are so far away that their annual shift of position in the sky is too
small to see without a good telescope.
How far away would a star with a parallax angle of 0.2 arcsec be from us? -
✅✅5 parsecs
Answers
What was the surprising finding of Cecilia Payne's 1925 doctoral thesis on the
elemental composition of star - ✅✅All stars are composed of mostly hydrogen
and some helium, with only traces of other elements.
What process is primarily responsible for powering the light emitted by most
stars? - ✅✅nuclear fusion of hydrogen into helium
The inward crushing force of the Sun's mass under its own gravity is balanced by
the outward explosive pressure from heat released by fusion in the core in an
example of - ✅✅equilibrium.
Where does the energy released by fusion of hydrogen into helium come from? -
✅✅The difference in mass of the hydrogen and helium is converted to energy
in the form of heat.
What was Annie Jump Cannon's insight into spectral classes? - ✅✅Spectral
classes should be ordered by temperature from hottest to coolest.
In searching for a planet very similar to Earth, which star is most similar to the Sun
and would therefor make the best candidate to study? - ✅✅61 Ursae Majoris
(class G8)
Order the following stars according to spectral class from hottest to coolest. -
✅✅1.
, Spica (B1)
2.
Sirius (A0)
3.
Polaris (F7)
4.
The Sun (G2)
5.
Capella (G3)
6.
Trappist-1 (M8
As astronomers use the term, the parallax of a star is - ✅✅one half of the angle
that a star shifts when see from opposite sides of the Earth's orbit.
Stars with larger parallax angle are __________ stars with smaller parallax angle. -
✅✅closer than
Why did it take astronomers until 1838 to measure the parallax of the stars? -
✅✅he stars are so far away that their annual shift of position in the sky is too
small to see without a good telescope.
How far away would a star with a parallax angle of 0.2 arcsec be from us? -
✅✅5 parsecs
