Download Round 1

Round 1
Round Hard Things
Value Clue
$200
The surface of Venus is kept very hot by the heat trapping properties of this in the
atmosphere. (CO2 )
$400
This is responsible for the presence of the asteroid belt (instead of a ninth planet).
(tidal forces due to Jupiter)
$600
This is how we discovered the rings around Uranus. (Occultation)
$800
These two planets most closely resemble the composition of the Sun and the solar
nebula. (Jupiter & Saturn)
$1000 Within the Roche limit of a planet, this will happen to a gravitationally bound object.
(Ripped apart by tidal forces)
Round?
Value
$200
$400
Things
Clue
These are the two main methods of detecting exoplanets. (Doppler shift and transits)
The recently launched Kepler satellite is looking for exoplanets using this method.
(transits)
$600
In a star/planet system, both the star and the planet orbit this. (center of mass)
$800
The tails of comets are formed by this. (Solar heating)
$1000 This is why a spinning cloud of gas and dust forms a disk and not a sphere. (conservation of angular momentum)
Round Hot Things
Value Clue
$200
These tell us about the composition of the outer layers of stars. (absorption lines)
$400
Spectral classification of stars is based mostly on this. (temperature)
$600
This is the factor by which the luminosity of a star changes when its radius is increased
by a factor of 3. (9)
$800
These allow us to determine the masses of stars. (eclipsing binaries)
$1000 These contain 10’s to 100’s of thousands of old stars. (globular clusters)
Misc.
Value
$200
$400
$600
$800
Clue
These can come from the Oort cloud and sometimes visit the Sun only once. (comets)
A ’shooting star’ is actually this. (meteor)
This is the event that killed the remaining dinosaurs and 2/3 of all life. (K-T extinction)
A nova can result when you have these two objects near each other. (White dwarf and
other star like red giant)
$1000 Variable stars are useful to astronomers because they allow you to tell this. (the distance
to the star)
Round 2: Double Jeopardy
Great Ball of Fire
Value Clue
$400
This is a violent release of energy from the Sun. (solar flare)
$800
This is considered the ’visible’ surface of the Sun. (photosphere)
$1200 Every 11 years, the Sun reverses this. (magnetic polarity)
$1600 This is the approximate temperature of the Sun’s core. (107 K or 10 million K)
$2000 Sunspots appear dark because of this. (strong magnetic field)
A Star
Value
$400
$800
$1200
is Born...and Dies
Clue
This is the source of energy for main sequence stars. (hydrogen fusion)
Before reaching the main sequence, a protostar is doing this. (contracting due to gravity)
A star becomes a red giant when this happens. (runs out of hydrogen to fuse in its
core → leaves the main sequence)
$1600 A Type 1a supernova occurs when a white dwarf’s mass exceeds this. (1.4 M )
$2000 This prevents the collapse of the star at the center of a planetary nebula. (electron
degeneracy pressure)
More Round Hot Things
Value Clue
$400
This ’failed star’ did not have a high enough temperature to sustain long-term fusion.
(brown dwarf )
$800
An ’HR diagram’ is a plot of which two quantities. (T (or spectral type) vs. L (or
absolute magnitude))
$1200 More luminous stars tend to live this. (shorter lives)
$1600 This tells you how much energy is released in the fusion of hydrogen to helium. (E =
∆mc2 where ∆m is the mass difference between the input H’s and output He’s.)
$2000 Stars are in hydrostatic equilibrium, which means that this supports them against
gravitational collapse. (thermal pressure due to nuclear reactions in the core)
Misc.
Value
$400
$800
Clue
This event releases heavy elements into space. (supernova)
When an iron core from a large star collapses, this type of new star can form. (neutron
star)
$1200 A star with a parallax of 0.05 arcseconds is this far away. (20 pc)
$1600 Stars spend most of their ’active’ life in this phase. (main sequence)
$2000 This is how astronomers determine the age of a star cluster. (main sequence turn-off )
Round 3: Final Jeopardy
Category: Stellar Evolution
Question: Fill in the circles in the stellar evolution flow chart below.
black hole
n
Su
_M
>_
M
.08
0
>
n
Su
protostar
M
<>___
_
M
<_
_
Sun
<0
.08
Solution:
MS
red giant
Su
red giant
M
n
n
>_
M
.08
0
>
n
Su
un
S
<0 .08 M
>.0 8 M
Sun
protostar
0M
<>_8-1
_
M
main
Su
n
sequence
>8
-1
0M
Sun
Su
n
<0
.08
MS
Type __
supernova
black hole
Type __
supernova
black hole
un
Su
_M
protostar
supergiant
n
Su
un
S
<0 .08 M
>.0 8 M
protostar
Sun
supergiant
un
brown
dwarf
supergiant
supergiant
Type __
supernova
Type __
II
supernova
red giant
red giant
planetary
nebula
black hole
neutron
stars
white
dwarf