USU PHYS 3100 Exam 4

What is the distance from the Earth to the Sun in AU, miles and Sun diameters?
- 1 AU, 93 million miles, ~100 Sun diameters
How does the Sun’s diameter compare to the Earth’s diameter?
- The Sun's diameter is roughly 109 times larger than Earth's diameter.
How does the Sun’s mass compare to the Earth’s mass? Jupiter’s mass?
-The Sun's mass is roughly 300,000 times greater than Earth's mass. 1,000 times greater than Jupiter’s mass
What percent of the Sun’s mass is composed of elements heavier than helium?
- 2%
What is the average rotation period of the Sun?
- 27 days
What is the surface temperature of the Sun ( ̊F)?
- 10,000 F
What is the power output of the Sun?
- 4 × 10^26 Watts (400 YotaWatts)
What is the source of the Sun’s energy?
- Fusion
What is the temperature of the core of the Sun ( ̊F)?
- 27 Million Degrees F (15 Million K)
What percent of the Sun’s total mass has been converted into energy during the 5 billion years
that the Sun has been shining?
- Less than 0.1%
What kind of particles are used to study the Sun’s core?
- Neutrinos
What is the solar neutrino problem?
- The number of neutrinos was less than expected
What is the solution to the solar neutrino problem?
-The solution involved the discovery that neutrinos come in different flavors and can change flavor as they travel through space.
Put the following layers of the Sun in order from the center of the Sun to its outer atmosphere:
chromosphere, convective zone, core, corona, photosphere, radiative zone.
- Radiative zone, Convective zone, Photosphere, Chromosphere, Corona
What causes sunspots to be cooler?
- Stronger magnetic fields
What is the period of the solar cycle from maximum solar activity to maximum solar activity?
- 11 Years
What causes the solar cycle?
- Differential Rotation
In what layer of the Sun’s atmosphere are spicules found?
- the Chromosphere
Define solar prominence
- A large, bright loop of cool, dense gas that erupts from the Sun's surface and can loop back down for days or weeks.
Define solar flare
- A sudden, intense burst of radiation from the Sun's surface, lasting from minutes to hours.
Define coronal mass ejection.
- A large-scale eruption of plasma and magnetic field from the Sun's corona.
Which lasts longer a solar prominence or a solar flare? Which did we see when we looked at
the Sun?
- Prominences
What is the solar wind mostly composed of?
- Protons and electrons
Which mission made three solar scans at all latitudes?
- Ulysses
Which mission was able to see the whole Sun?
- SOHO
Which mission has a set of postage stamps?
- SDO
Which mission is studying the Sun up close?
- Parker Solar Probe

How much more light gathering power does an 8-inch telescope have compared to a 4-inch
telescope?
- Four times
What is resolving power?
- Ability to discern details
What is the purpose of adaptive optics? How does adaptive optics work?
- Helps overcome atmospheric distortions by adjusting the mirror in real time
What advantage does the Hubble Space telescope have over telescopes located on the surface
of the Earth?
- It is above the atmosphere
Why can you see more stars in rural areas than is urban areas?
- Less light pollution
What are the advantages of a bigger telescope?
- Gathers more light, and greater resolution
Why are there no X-ray telescope located among the Mauna Kea observatories?
- X-rays are stopped by Earth’s atmosphere
What country? Extremely Large Telescope (ELT)
- Chile
What country? Gemini North
- USA
What country? Gemini South
-Chile
What country? Gran Telescopio Canarias (GTC)
-Spain
What country? Hobby-Eberly Telescope (HET)
-USA
What country (location)? Hubble Space Telescope (HST)
- Low Earth Orbit
What country (location)? James Webb Space Telescope (JWST):
- L2 Lagrange Point (orbit around the Sun)
What country? Keck Telescopes (Keck I & Keck II):
- USA
What country? Large Binocular Telescope (LBT):
-USA
What country? Subaru Telescope
-USA
What country? Southern African Large Telescope (SALT):
-South Africa
What country? Very Large Telescope (VLT)
-Chile
What makes Mauna Kea a near ideal location for observatories?
- Dark skies, good seeing, low humidity, high elevation, low latitude
Which of the largest telescopes in the world are located on Mauna Kea?
- Keck Telescopes, Subaru telescope, Gemini North
Which observatories on Mauna Kea were part of the Event Horizon Telescope that produced the
first image of a black hole?
- SMA, JCMT
What is the approximate baseline of the Event Horizon Telescope?
- The Event Horizon Telescope has a baseline that spans the diameter of the Earth.
What country? ALMA
- Chile
What country? APEX
- Chile
What country? James Clerk Maxwell Telescope
- Hawaii
What country? Large millimeter telescope
- Mexico
What country? Pico Veleta Observatory
- Spain
What country? South Pole Telescope
- South Pole
What country? Submillimeter Array
- Hawaii
What country? Submillimeter Telescope
-Arizona
Which observatory is the largest array in the Event Horizon Telescope?
-ALMA
Which is the southern most observatory in the Event Horizon Telescope?
- SPT
Which observatory in the Event Horizon Telescope is located by the Large Binocular Telescope?
- Submillimeter Telescope
Which is the northern most observatory in the Event Horizon Telescope?
- Pico Veleta Observatory
Which observatory has the largest telescope in the Event Horizon Telescope?
- Large Millimeter Telescope
Which observatory in the Event Horizon Telescope is located at the highest elevation?
- APEX
Which observatory in the Event Horizon Telescope is an array of 8 – 20 foot telescopes?
- Submillimeter Array
At what wavelength did the Event Horizon Telescope make its observations?
- 1.3mm
In what month in 2017 did the Event Horizon Telescope make its observations of M87*?
- April
How were the telescopes in the Event Horizon Telescope synchronized?
- Atomic clocks
How much total data was collected by the Event Horizon Telescope to produce the first image
of a black hole?
- 5 petabytes (5,000 Terabytes)
How was the Event Horizon Telescope data brought together?
- FedEx
What caused a six month delay in sending the data from one of the Event Horizon Telescope
observatories?
- No flights from the south pole in the winter
What is the name of the black hole at the center of our galaxy?
- Sagittarius A*
How does the mass of the black hole at the center of our galaxy compare to the mass of M87*?
- M87* is 1,000 times more massive
How does the size (diameter) of the black hole at the center of our galaxy compare to the size
of M87*?
- M87* is 1,000 times bigger
Why does the black hole at the center of our galaxy appear to be the same size in the sky as
M87*?
- Sagittarius A* is 1,000 times closer
Why is it so difficult to directly image an exoplanet?
- Stars near them are too bright
Why is the James Webb Space Telescope a good choice for directly imaging exoplanets?
- It is an infrared telescope
What are the three main methods for detecting exoplanets?
- Astrometric Technique, Radial Velocity Technique, Transits & Eclipses
Which method works best for close stars with distant massive planets?
- Astrometric Technique
Which method works best for massive planets that are close to their stars?
- Radial Velocity Technique
Which method likely only works for 1% of stars?
- Transits & Eclipses
How many stars did the Kepler Mission watch for transits?
- 150,000
Which method(s) can be used to determine the orbital period of exoplanets?
- Astrometric Technique, Radial Velocity Technique, Transits
Which method(s) can be used to determine the eccentricity of exoplanets?
- Radial Velocity
Which method(s) can be used to determine the size of exoplanets?
- Transit method
What two methods are used to determine the density of exoplanets?
- Radial Velocity and Transit
How many confirmed exoplanets have been discovered to date?
-5,600+
Which method has been used to discover the most exoplanets? What percent?
-Transit (74.3%)
What percent of confirmed exoplanets are terrestrials?
- 4%
What kind of planet was the first exoplanet found around a Sun like star?
- Hot Jupiter (51 Pegasi b)
How many planets have been discovered orbiting TRAPPIST-1?
- 7
HAT-P-32 b has a density similar to?
- A puffed up marshmallow (not dense at all)
What is the name of the exoplanet that is closest to Earth?
- Proxima b
What kind of rain falls on the nightside of WASP-76 b?
- Iron