WorksheetsStar Formation
Total questions: 16
Worksheet time: 8mins
How do single stars form within huge clouds of interstellar gas and dust?
Clouds fragment into smaller objects, forming many stars at one time.
One star forms; other matter goes into planets, moons, asteroids, & comets.
Clouds rotate & throw off mass until only enough is left to form one star.
What is a T Tauri star?
a collapsing cloud of gas about to become a protostar
a dying star
a cool main sequence star
a star releasing a planetary nebula
a protostar about to become a star
Objects more massive than our Sun form into stars
much slower, over billions of years.
in about the same time.
much faster, over tens of thousands of years.
not at all – they are unstable.
Stars are often born within groups known as
clans.
spiral waves.
aggregates.
clusters.
swarms.
All stars in a stellar cluster have roughly the same
temperature.
color.
distance.
mass.
luminosity.
Very young stars in small clusters of 10–100 members are known as
OB associations.
molecular cloud complexes.
aggregates.
globular clusters.
hives.
Globular clusters are typically observed
in the plane of our Galaxy.
above or below the plane of our Galaxy.
near to our Sun.
in the hearts of other galaxies.
Stars in clusters & associations have about the same
age.
temperature.
mass.
color.
luminosity.
A key feature of globular clusters is that they have
very few cool stars.
the oldest stars in our Galaxy.
lots of massive main sequence stars.
stars with very different ages.
high concentrations of metals.
Some regions of the Milky Way’s disk appear dark because
there are no stars there.
stars in that direction are obscured by interstellar gas.
stars in that direction are obscured by interstellar dust.
numerous black holes capture all the starlight behind them.
When a star’s
visible light passes through interstellar dust, the light we see
is dimmed and reddened.
appears to twinkle.
is Doppler shifted.
turns bluish in color.
ionizes the dust and creates emission lines.
Astronomers use the term nebula to refer to
outer envelopes of dying stars that drift gently into space.
remnants of stars that die by supernova.
clouds of gas and dust in interstellar space.
distant galaxies seen beyond our Milky Way.
all of the above.
Interstellar gas is composed primarily of
90% hydrogen, 9% helium, and 1% heavier elements.
molecules including water and CO2.
50% hydrogen, 50% helium.
hydrogen, oxygen, and nitrogen.
99% hydrogen, and 1% heavier elements.
The reddish color of emission nebulae indicates that
gas and dust is moving away from Earth.
hydrogen gas is present.
dying stars have recently exploded.
cool red stars are hidden inside.
dust is present.
21-centimeter radiation is important because
its radio waves pass unaffected through clouds of interstellar dust.
it arises from cool helium gas present throughout space.
it can be detected with optical telescopes.
it is produced by protostars.
it reveals the structure of new stars.
Complex molecules in space are found
in the photospheres of red giant stars.
primarily inside dense dust clouds.
in the coronas of stars like our Sun.
scattered evenly throughout interstellar space.
surrounding energetic young stars.
