Astronomy Exam 1: Final Exam Review

If the Sun instantaneously stopped giving off light, what would happen on Earth?
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Terms in this set (33)
If the Sun instantaneously stopped giving off light, what would happen on Earth?
Earth would get dark about 8 minutes later
You distinguish one type of atom (e.g., iron, copper, zinc, etc.) from another by looking at how many __________ it has
protons
When any type of wave increases in frequency as its source moves toward you, it is manifesting which of the following physical phenomena?
Doppler effect
Which of the following sequences of electromagnetic waves is in the right order from shorted to longest wavelength?
gamma-rays, x-rays, ultraviolet, optical, infrared
As a blackbody becomes hotter, it also becomes ____________ and _____________.
more luminous, bluer
If you double the size of the primary aperture of an optical telescope, what happens to the light-gathering power?
it quadruples
Only two portions of the electromagnetic spectrum can be easily seen from the ground because the atmosphere is transparent to them. Which ones are they?
optical and radio
Which of the following best describes the function of resolution?
It lets you see fine detail in objects
Let's say that you have an interferometer made up of two telescopes that is tuned to operate at 2 microns (=2x10^-6 meters). The telescopes are separated by 85 meters what is the resolution?
0.005 arc seconds
Arrays of radio telescopes produce much better resolution than single-dish radio telescoped can because they work based on the principle of
interference
Before coming to UGA, Dr. Magnani worked at which of the following radio telescope observatories?The Arecibo ObservatoryIf you double the size of the primary aperture of an optical telescope, what happens to the resolution?It is halved.Cameras that use adaptive optics provide higher-spatial resolution images primarily becausedeformable mirrors are used to correct the blurring due to the Earth's atmosphereThe angular resolution of an optical ground-based telescope is usually determined byatmospheric seeingIf we could increase the quantum efficiency of the human eye, doing so wouldallow humans to see better at night or in the low-light environmentsIf a star has 1x10^6 km and blackbody surface temperature of 10,000 K, what is its luminosity?7.1 X 10^27 Joules/sIf the wavelength of electromagnetic radiation double, what happens to its frequency?It is halvedIf the wavelength of electromagnetic radiation doubles, what happens to the energy of a photon with that wavelength?It is halvedWhat is the relationship between Luminosity and Flux?L=4pid^2FWhat is a photon?Light behaving as a particleTemperature is a measure ofthe speed of the particles in a regionIf a radio station broadcasts at 91.7 MHz, what is the equivalent wavelength of this radio wave?3.27You observe a spectral line of hydrogen at a wavelength of 702.3 nm in a distant galaxy. The rest wavelength of that line is 578.1 nm. What is the radial velocity of the galaxy?64,000 km/sIs the galaxy from problem 23 moving towards us or away from us?away from usTwo stars (call them A and B) appear to have the same brightness, but star A is 3 farther away than Star B. Which is more luminous and by how much?A is nine times more luminous than BA plot of the intensity of light as function is calleda spectrumIf you double the temperature of a blackbody, what happens to its flux?It goes up by a factors of 16When I look at a distant blackbody source with a cloud of cold, low-density gas between us and the blackbody source, what type of spectrum will I see?absorption line spectrumIf I were to look just at the cold cloud in problem 28, with no blackbody source behind it. what type of spectrum will I see?emission line spectrumAn interferometer is much better than a single-dish radio telescope forseeing bright, point-like objectsA blackbody is a perfect absorber anda perfect emitterWhich of the following optical color has the longest wavelength?RedWhich of the following optical colors has the most energy?Blue